ELEMENTYour Guide to Foundries in Pakistan
www.pfa.org.pkSpecial Edition 2017
Industrializing Pakistan
MILLAT TRACTORS LIMITED
ththth INTERNATIONAL FOUNDRYINTERNATIONAL FOUNDRY
CONGRESS & EXHIBITIONCONGRESS & EXHIBITION
INTERNATIONAL FOUNDRY
CONGRESS & EXHIBITIONFEB. 15-16, 2O17, Pearl Continental Hotel, Lahore FEB. 15-16, 2O17, Pearl Continental Hotel, Lahore FEB. 15-16, 2O17, Pearl Continental Hotel, Lahore
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I welcome all the participants to the 6th International Foundry Congress &
Exhibition (IFCE-2017) on 15th-16th February, 2017, at Pearl Continental
Hotel Lahore, Pakistan. It is heartening to note the wide participation of
local and international casting producers, machinery manufacturers,
foundry materials suppliers and service providers, and global foundry
technologist from various countries.
Pakistan Foundry Association is honored by the participation of China
Foundry Association for the first time. We acknowledge the presence of
Chinese machinery suppliers, Indian multi nationals, Turkish Companies,
Magmasoft, leading German foundry Software Company, Chukurova
Kimya-Turkish foundry chemicals producers, TCT- German machinery supplier, VoxelJet AG- 3D Printing
solutions for product development, and Saint Gobain – Furnace refractory producers from France.
We are encouraged with the participation and of leading Pakistani foundries and engineering companies
especially Millat Tractors, Bolan Castings, KSB Pumps Pakistan, Qadri Group of Companies, Chenab
Engineering (Pvt.) Ltd., Excel Group, Karachi Shipyard, Pakistan Ordinance Factory (POF), and all
members of PFA.
This year, subject focused seminars and training workshops by the global foundry technologist from
various countries will be held parallel to the exhibition. New foundry technologies will be introduced and
current technical issues will be addressed.
I foresee the foundry simulation software, 3D printing machine and surface treatment solutions are the
future for local foundry industry to produce high quality castings for national and international markets.
I recommend all foundry men, technical entrepreneurs, and heads of various companies, teachers of
technical schools and Universities, and engineers to benefit from the above sessions.
IFCE-2017 is a great opportunity for all foundry businessmen to discuss advancement with their
counterparts and develop joint ventures.
I wish you all a great success in IFCE-2017 and wish you a memorable event.
-0300 8673873
Joint SecretaryPakistan Foundry Association
Different Methods of sg Iron Production
with their Tehnical and Economical
Advantages and Disadvantages
th50 Census of World Casting
Production
3D Printing: Turbocharging Casting
Processes of all Kinds
RASTGAR AIR COMPRESSORS
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Casting Simulation: FAQ and Answers 20
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3D Printing: Turbocharging Casting
Processes of All Kinds
Ingo Ederer
CEO, Voxeljet, Germany
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Jhumra Road Nishatabad, Faisalabad, Pakistan
Fax : 0092 41 8752482
E-mail : [email protected]
web : www.chenabfoundries.com
Tel : 0092 41 8751048
0092 41 8751424
0092 41 8751423
Application Details
Based in Stanhope, County Durham, Astrum is a
specialist steel foundry making components and
assemblies for military ghting vehicles, ground
engaging tools for the construction industry and
wear parts for the mining industry. In 2008, due to
rising energy prices, Astrum embarked on a
programme of improving the energy efciency of
its processes.
Mike Hutchinson, operations director at Astrum
explains, One of our key areas of spend is our
compressed air system, which is critical to the
performance of our plant and is fundamental to
our processes for moving sand around the
foundry and for operating industrial equipment.
As part of our programme of improving the energy
efciency of our processes, we looked to replace
existing compressors and approached CompAir
distributor, Air Energy Management to assess our
air requirements.
A i r Ene rgy Managemen t was ab le t o
demonstrate that by looking at the overall
efciency of the existing system, and making sure
it is designed specically for our needs, we could
save a signicant amount of money.
Carbon Trust
To accelerate its investment plans, Astrum
approached the Carbon Trust and was awarded
an interest free loan through its Big Business Ret
scheme, which aims to provide businesses with
zero-cost capital to invest in new high
performance, energy efcient equipment.
CompAir is a world-class organisation, it has
extremely energy efcient air compressors and its
support services are second to none. ' '
Richard Dainton, managing director, Air Energy
Management
Two regulated-speed comressors from Com pAir
have helped Astrum, a steel components
manufacturer, to cut its compressed air energy
costs by more than a half and increase
productivity at its foundry in Country Durham.
Astrum was able to benefit from an interest-free
loan from the Carbon Trust to fund the
installation,
thanks to the high energy efficiency of its new
compressed air system.
Be nets-at-a-glance
Ÿ 50% reduction in compressed air energy
Ÿ costs saving over £80,000 per annum
Ÿ High quality, extra dry air
Ÿ Increased productivity
Ÿ Backup compressor for
Ÿ increased production reliability
Ÿ Hot air ducting saving £1 0,000 per year in
heating costs
Ÿ Number of air receivers reduced from 16 to 3
RASTGAR AIR COMPRESSORS
How a British Foundry Reduced Energy Costs by 50%
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Imtiaz A Rastgar
Hutchinson comments, The Carbon Trust loan
enabled us to install a system that will not only cut
power consumption, but will also improve the
efciency of our business.
The loan will pay for itself within four years
through energy savings alone, and has provided
a cost effective way for us to upgrade crucial
equipment.
Bespoke system
Working alongside Astrum and CompAir, PJr
Energy Management developed a bespoke
system to reduce the demand on compressed air
at the foundry; and replaced old, large
compressors with two more efcient, smaller
CompAir compressors.
The CompAir L75 RS and L 160 RS compressors
both feature regulated-speed technology and are
protected and monitored by a Delcos 3100
electronic control system.
Both compressors are linked to a aw measuring
system, allowing operators to check airow,
allocate costs to different departments and
pinpoint any leakage. In addition to compressors,
CompAir also supplied energy efcient thermal
mass refrigerant and desiccant dryers.
The new system will reduce MrurrB compressed
air energy demand by 1 ,255,000 kWh and save it
over £80,000 per annum.
Additional infonnation
A CompAir L75 RS regulated-speed compressor
is located in a small compressor house at the
foundry and provides air at 7.5 bar to a bore blast
machine for optimum surface quality.
The L75 Ra; regulated-speed drive technology
matches compressor ow to plant demand with
great efdency. This means that the unit produces
the correct volume of air required by the
application at all times. The unit is suitably sized
to serve a second bore blast machine, should it
be needed.
CompAir overhauled an existing compressor to
provide system redundancy. Previously, Mrum
did not have any backup, meaning that if a
compressor stopped working, production would
be brought to a halt.
Hot air venting from the small compressor house
ensures that 80% of the energy lost in the
compression process is reclaimed. The hot air is
ducted into the foundry during winter and out into
the atmosphere in the summer, allowing Mrum to
tum off heaters, saving £1 0,000 per year in diesel
costs.
The second CompAir compressor, an L 160 RS
regulated-speed unit with Delcos 31 00 controller,
is located in one of the main compressor houses.
Working alongside overhauled exist ing
compressors, the unit provides air for the 5,000-
litre main foundry receiver.
Hot air from this compressor room, and exhaust
air from the receiver is again ducted into the
foundry. A control valve ensures that the receiver
can be shut off from the compressor house to
eliminate leakage.
The number of air receivers at the Mrum site has
been reduced from sixteen to just three, thanks to
a more efcient use in the new system.
In addition to the two compressors, CompAir has
also supplied a desiccant dryer, providing the
extra dry air required by a molding machine. The
new system also includes low-pressure drop
piping, and a leak detection programme. A ow
measuring system brings information from all
meters into one control panel, allowing operators
to check airow, allocate costs to different
departments and pinpoint any leakage.
Tel: +92 51 222823, Email: [email protected],
www.rastgar.com
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mould density and interfacial heat transfer
coefficients). Widely used cast metals (like iron,
steel, aluminium, copper, magnesium and zinc
alloys) and major casting processes (green sand,
investment shell, gravity die, and pressure die)
can be handled by most simulation programs
available today.
2. Which physical phenomena related to
metal casting can be simulated?
There are three major phenomena. The first is
mo l ten me ta l flow ing i n to the mou ld ,
accompanied by falling, splashing, streams
separating, rejoining, and onset of freezing. The
second is metal sol idification, which is
accompanied by changes in volume and
formation of microstructure. The third is metal
cool ing to room temperature, which is
accompanied by stresses and distortion.
Solidification simulation is a mature technology.
Coupled simulation of two or more events is
complex, requires more computation time and is
usually less accurate.
3. Which cas t ing processes and
phenomena can be s imula ted more
accurately?
Gravity casting processes, in which casting
solidification time is much longer than mold filling
time, can be accurately modelled and simulated
since only physical phenomenon (metal
solidification) has to be handled. An example
would be heavy steel castings produced in sand
molds. On the other hand, pressure die casting is
much more difficult to simulate accurately, since it
involves simultaneous multi-physics phenomena
of metal droplet spray at high velocity
instantaneously solidifying against the metal die
walls.
Abstract
A number of simulation programs are available
today to visualize mold filling and casting
solidification. Such virtual trials save the time and
production resources otherwise required for
shop-floor trials. The simulation results provide
the necessary insight to determine the cause of
past defects (hindsight) or prevent future defects
(foresight). The methods design is iteratively
modified and simulated till the desired quality and
yield are achieved. The simulation programs are
also useful for checking the castability of a part
design, early in its lifecycle, when it is easier to
modify and achieve significant cost reduction.
Most of these programs claim to be versatile,
intelligent, accurate, user-friendly and cost-
effective. But many doubts prevail. This
compilation includes the most frequently asked
questions by foundry engineers collected over
the last 20 years, and their answers by experts.
The questions and answers are not specific to
any particular casting simulation program. They
are divided into three parts, each with 15
questions. Part I includes the applications and
benefits; Part II includes user inputs and results;
and Part III includes their selection and optimal
use.
PART I: Applications and Benefits
1. Which casting metals, processes and
phenomenon can be simulated?
In theory, any metal that can be melted and
poured into a mould can be simulated. In practice,
simulation is limited to only those metals and
processes for which relevant data is available.
This includes thermo-physical properties of metal
(like specific heat and viscosity at various
temperatures) and process characteristics (like
Casting Simulation: FAQ and Answers
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Dr. B. Ravi, Institute Chair Professor,
IIT Bombay, Mumbai
4. What are the typical / essential
modules of casting simulation software?
There are three major modules of casting
simulation software. The Pre-processor takes
various inputs from the user, and sub-divides the
entire mould along with casting, into a mesh of
small elements. The Solver computes the
temperature, velocity and other results at each
element as a function of time. The Post-processor
displays the results as colour-coded plots for
visualization. Some casting programs have
modules based on the type of mold or process
(ex. sand, die, or investment casting). These
con ta in p rocess-spec ific var ia t ions o f
mathematical models and material databases.
5. What are the most important results
from casting simulation?
Flow simulation gives the location, velocity and
pressure of molten metal front during mould
filling. Solidification simulation gives the
temperature and cooling rate in all locations
inside the casting and mould. Further simulation
can provide phase distribution, microstructure,
cooling stresses and casting distortion. All these
results are displayed as colour-coded plots at
different instants of time and can be played like a
video animation. The results can usually be
viewed in 3D as well as 2D cross-sections.
6. Which cast ing defects can be
predicted by computer simulation?
Solidification-related defects: shrinkage cavity
and porosity, can be accurately predicted by most
simulation software. This is followed by flow-
related defects: cold shut, misrun and sand
inclusion. Blow hole and gas porosity are difficult
to predict since they depend on a lot more shop-
floor conditions which cannot be captured in
simulation. Cooling-related defects: hot-tear,
distortion and hard-spots can be predicted by a
few simulation software, though with a lower level
of accuracy.
7. Can we improve the quality and yield
of a casting by simulation?
Simulation by itself does not improve casting
quality and yield of a casting, but enables a
casting engineer to virtually try-out different
combinations of methods design and process
parameters to identify the one that gives the
des i r ed qua l i t y w i t h good y i e l d . The
improvements in quality and yield, and the time
taken to achieve them, depend on the experience
of the casting engineer in interpreting the
simulation results, methoding knowledge for
improving the casting design, and understanding
of process capabilities for implementing the same
on the shop-floor.
8. How much time is required for one
simulation run?
The actual computation time (simulation solver)
ranges from a few minutes to several hours,
depending on casting model, type of results, and
computer configuration. Large parts (in terms of
file size) need to be divided into more number of
elements and hence require more computation.
Simulation of only mold filling or only casting
solidification takes less time than coupled
simulation of both phenomena. Some casting
programs allow quick simulation for initial
iterations. Full simulation is carried out only for
the last iteration (usually in night time) for
verification.
9. How many iterations are needed /
possible to optimize quality and yield?
There is no upper limit for the number of iterations
that can be performed using casting simulation
software. In practice, this is limited by the target
(desired quality and yield) and the time available.
Each iteration requires modification of methods
design, which depend on the foundry knowledge
of the engineer. In most cases, acceptable
targets can be achieved within 5-10 iterations of
methods modification and quick simulations
followed by a full (detailed) simulation to verify the
final design. All these can be completed usually
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within a week.
10. Can simulation software create gating
and feeder models?
Most simulation programs expect the users to
create the mould cavity layout with gating and
feeders in a separate 3D CAD program, and
import the entire casting for simulation. Based on
the results, the users have to go back to the CAD
program, make suitable changes, and re-import
the model for simulation. Some simulation
programs include basic solid modeling facilities to
reduce the above hassle. Very few programs
provide integrated design, 3D modeling,
simulation and optimization of methods design.
11. Can simulation software optimize the
gating and feeder designs?
Optimization implies achieving the desired
quality along with high yield by iterations of
simulation, interpretation of results, and
modification of methods design. All of these tasks
require human intervention. Some software
programs provide initial design and models of
gating and feeding, which helps in minimize the
number of iterations. A few others run multiple
simulations driven by user-defined criteria and
range of design parameters, but this can take
several hours for complete results.
12. What are the economic benefits of
casting simulation to a foundry?
The most tangible (measurable) benefit is energy
saving due to improvement in yield and quality,
and increased capacity without adding more
equipment. New casting development time is
usually compressed to one third (from several
weeks to just days), which is important for jobbing
foundries. Production foundries can halve their
total rejections (say, from 8% to 4% overall).
13. What are other (intangible) benefits of
casting simulation to a foundry?
The main intangible benefit is higher customer
satisfaction through better quotes (since yield
can be accurate ly est imated) , qu icker
submission of first good sample casting (by rapid
virtual trials), and consistent quality for
subsequent shipments. Other benefits include
more orders (by projecting the simulation
capabilities of foundry), higher-value orders (by
taking up more difficult projects), and better
employee morale (better output and longer
retention).
14. Why OEMs increasingly insist on a
simulation report along with RFQ?
With Just in Time manufacturing philosophy
adopted by most of the original equipment
manufacturers, the cost of poor quality is much
higher today. Further, new product development
times have also reduced. Hence OEMs need to
be assured that a foundry is capable of quickly
developing a new casting, getting its quality 'right
first time', and also keep the quality consistent
('right every time'). A simulation report is the best
way to ascertain the capability of the foundry, and
is therefore expected along with Request For
Quote for new projects.
15. In what other ways simulation is useful
to OEMs?
Original equipment manufacturers use the
simulation results in many ways to improve
overall quality assurance. Simulation shows
difficult-to-feed areas (isolated hot spots), which
can be either reduced in magnitude, or provided a
feed path and feeder boss to ensure directional
solidification. Such part design changes, carried
out by OEM, can reduce the difference in weight
between the designed part and as-cast part,
which is often a major point of contention
between OEM and casting supplier. The
simulation results can also be used to identify
critical areas that need careful inspection, and
provide useful insights for collaborative solutions
through technical discussions.
PART II: User Inputs and Results
16. What are the major (essential) inputs
required from the user?
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Essential inputs for simulation include the 3D
CAD model of the casting along with gating and
feeders; mould and its elements including
cavities, cores, vents, and feedaids (sleeves,
covers, chills, coatings, etc.); specification of the
corresponding materials, and critical process
parameters (like pouring temperature and rate).
The casting model should include all allowances:
shrinkage, draft, fillets, machining, and distortion.
Any difference between the simulated model and
shop-floor casting will lead to a mismatch
between the virtual and real results.
17. Which default inputs are assumed by
the system, but user can provide own values?
There are many parameters that are required for
simulation and affect the accuracy of results, but
are difficult to input by the users, and hence
default values are assumed by simulation
programs. These include various interfacial heat
transfer coefficients (between metal-mould,
mould-air, metal-air, metal-chill, chill-mould, etc.),
limiting values for stoppage of metal flow and
feeding, various choices of assumptions and
approximations for optimizing computation
speed and accuracy. Since most of these are
neither easily understood nor available with the
users, their values are taken from databases
included with simulation software.
18. What is IHTC (interfacial heat transfer
coefficient)?
The IHTC represents the rate of heat transfer per
unit area per unit time, between a given pair of
materials. It usually accounts for all modes of
heat transfer: conduction, convection and
radiation. The most important IHTC is between
solidifying metal and surrounding mold. It is not
constant; it is high in the beginning, when the
temperature difference is large and the casting-
mold pair are in perfect contact. The IHTC
gradually reduces as the casting temperature
falls, mold temperature rises, and air gap
between them grows. The air gap itself is not
uniform and depends on casting shape.
19. How can we get the correct value of
IHTC (interfacial heat transfer coefficient)?
Simulation software usually provide the default
values of IHTC between important pairs of
materials: casting to mold, casting to chill, mold to
air, etc. The IHTC database contains the values
for different combinations of materials (ductile
iron casting to green sand mold, etc.). If the
values are not available for a particular
combination, then either experiments need to be
conducted by the user, and the data provided to
the software to generate and incorporate the
values in its database.
20. Can simulation programs handle a
new alloy composition provided by user?
Users can select an existing alloy or create a new
entry in the material database of the software,
and edit its composition. However, the thermo-
physical properties of the casting alloy are
required for simulation, and these values too
need to be entered. It is not easy to generate the
property values, since they require expensive
experimental faci l i t ies and experienced
technicians. Some software programs estimate
the property values based on composition, but
these are approximations, and need to be
verified.
21. What is the difference between FDM
and FEM based simulation programs?
FDM stands for Finite Difference Method, in
which the computation domain (casting and
mould) is subdivided into structured (brick)
elements. In Finite Element Method or FEM, the
subdivision uses unstructured elements (like
tetrahedrons). The latter can better approximate
the casting and mould geometry with fewer
elements, and thereby can give more accurate
results, but the mesh generation is usually more
cumbersome and error-prone. Most casting
software programs therefore prefer FDM and its
variations like Finite Volume Method (FVM) and
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Control Volume Method (CVM).
22. Can we use a general-purpose FEM
program for casting simulation?
A general-purpose FEM program can be used for
casting simulation, after incorporating the
relevant mathematical models for metal flow,
casting solidification and further cooling to room
temperature. The necessary databases of
temperature-dependent material properties (like
density, specific heat and thermal conductivity)
and process-dependent parameters (like
interfacial heat transfer coefficients) need to be
created. The program will need to be verified and
validated. All this requires a high level of research
expertise, time and effort, but gives the benefit of
an excellent understanding of casting process
modelling and computer simulation.
23. We only have 2D CAD drawings of
castings. Is it possible to simulate?
Simulation requires a 3D CAD model of the
casting, that too, a solid model (and not a surface
model) implying that all mass properties can be
computed. Any 2D drawings need to be manually
converted into solid models using a 3D CAD
software. Simple parts can be modelled within a
few minutes to an hour. Very complex parts like
gear boxes and engine blocks can take several
days to model, that too, by expert CAD engineers.
Once a 3D CAD model is prepared, it is easy to
store, view, modify and exchange, and to
evaluate using different types of simulation for
function, stress and manufacturing.
24. How can we get 3D CAD models of
castings for simulation?
There are three ways: (i) request the model from
the OEM customer or tool maker, (ii) approach an
engineering service provider, or (iii) create the
model in-house using a suitable CAD software
program. The level of difficulty increases from the
first to the last, but this is compensated by better
control on the output and other uses like design of
methods and tooling elements, inspection
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planning and CNC machining. Some of the model
formats (like .STL) cannot be modified, hence
OEMs are more willing to share these with their
vendors.
25. Can we use a 3D scanner to create the
CAD model of an existing casting?
Several types of contact and non-contact
scanners are available today to create a cloud of
points corresponding to the visible surface of the
casting. These points are then connected to
create the surface and eventually a solid CAD
model of the casting. Internal features, especially
narrow and curved holes cannot be scanned.
Non-contact scanners using white light or laser
are very fast (take only minutes) and fairly
accurate (less than 0.5 mm error).
26. What is the required format of 3D CAD
model file for casting simulation?
Most simulation programs support .STL format
(developed for 3D printing systems) owing to its
simplicity and robustness. An .STL file essentially
comprises (x, y, z) coordinates of the vertices of
triangles completely covering the 3D model, and
the outward pointing normal to those triangles.
Curved surfaces are approximated with flat
facets, leading to an error. This can be minimized
by finer faceting, which can be controlled during
file export. Increasing number of simulation
programs also support other neutral file formats
such as .IGES and .STEP.
27. After simulation, is it possible to
export the casting model to a 3D printer?
A few simulation programs allow iterative
modification, simulation and optimization of
casting models, especially the gating and
feeding. The full model of casting can be saved in
industry-standard formats (like STL or STEP).
This can be exported to a 3D printer for
fabricating the pattern. User has to ensure that
the required draft and allowances have already
been applied to the part model. Some programs
also allow the design of molds and cores, which
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can be printed on 3D sand printers.
28. Do simulation results always match
shop-floor observations?
C o m p u t e r s i m u l a t i o n s a r e b a s e d o n
mathematical models that are approximations of
the real-life. Metal casting process is highly
complex with a large number of parameters and
therefore impossible to simulate accurately. Still,
the results of solidification simulation, such as
shrinkage porosity location are fairly accurate.
Indeed, if the results do not match, one should
check if there are any discrepancies in what is
simulated and what is produced (for example,
size of gate or feeder neck).
29. How can we improve defect prediction
(location and size) by simulation?
Even the best simulation programs cannot
predict the exact location and size of casting
defects, which vary from casting to casting. The
prediction accuracy can be improved by
calibrating the software for a particular metal-
process combination, based on comparison of
simulation results with shop-floor observations
for multiple castings. With more simulations, the
users also gain better knowledge and experience
in interpreting the results, leading to better
predictions.
30. Can computer simulation replace
methoding engineers and shop-floor trials?
The casting simulation programs have come a
long way, and are very useful for quickly exploring
different methoding options for quality and yield
i m p r o v e m e n t w i t h o u t e x p e n s i v e a n d
cumbersome shop-floor trials. But simulation
programs cannot rep lace exper ienced
engineers, who can leverage their past
knowledge to find the best solution in difficult
cases. The results of simulation combined with
the analysis of experienced engineers provide
valuable insight, which is useful to analyse past
mistakes (hindsight), and confidently develop
new castings with minimal shop-floor trials
(foresight).
PART III: Selection and Use
31. How many cas t ing s imula t ion
software programs are available today?
There are more than a dozen commercial casting
simulation programs available today, developed
by vendors from different countries in Asia
(including India), Europe and USA. Given the
complexity and long development time, it is no
surprise that the heart (Solver) of most programs
or ig ina ted in lead ing un ivers i t ies and
Government research labs worldwide, starting in
1980s. Most of the recent improvements carried
out by the respective development teams have
been for improving the graphical user interface
and computational performance.
32. What are the evaluation criteria for
purchasing casting simulation software?
There are three major criteria to evaluate the
suitability of a simulation software for a particular
organization. The first is functionality, which
means that the software specifications should
meet the desired requirements. The second is
usability, which implies that the organization can
indeed get the desired results with the available
human resources. The third is cost effectiveness,
which is measured by the tangible and intangible
benefits against the investments (fixed and
variable costs).
33. How can we evaluate the functionality
of casting simulation software?
The software functionality can be initially checked
by going through its brochure and technical
specifications, industrial case studies, and
feedback of similar customers. Then a
benchmarking exercise should be carried out for
a defect-prone casting produced in the foundry.
Only the casting model and methoding layouts
should be provided; not the defect location for
each layout. Such a blind test will conclusively
prove the accuracy of the simulation software in
predicting the casting quality.
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34. Are casting simulation programs user-
friendly? How do we know?
Most software programs claim to be user-friendly,
but this can be far from true, especially for foundry
engineers who have little or no previous
experience in CAD and FEM. The best way to
ascertain the usability is to organize a live
demonstration, preferably for one of the problem
castings produced by the foundry. This can give a
clear indication of the types of inputs, decisions,
technical knowledge, and time involved. The
quality of initial training, frequency of use (at least
once every week) and continued technical
support by the software vendor also greatly
contribute to the software usability.
35. What are the costs involved in
establishing a casting simulation facility?
Initial costs include benchmarking exercise and
evaluation, software l icense (annual or
permanent option), computer hardware, and site
preparation (room, furniture, AC). The cost of
training and technical support for one year is
usually built into the initial cost. Major recurring
costs include salary of the simulation engineer,
and maintenance of software and hardware.
Software maintenance costs usually include
minor upgrades, besides technical support over
e-mail and phone.
36. What is the typical ROI for casting
simulation software?
The return on investment for casting simulation
software depends on the initial cost, usage
(number of casting projects per year), order
weight of simulated castings, and reduction in
wastage of production resources. For typical
casting simulation software implemented in a
medium size jobbing or production foundry, the
initial investment can be usually recovered within
a few months. It is often possible to recover the
software cost with a single project involving an
important large order.
37. Why are casting simulation software
very expensive compared to CAD?
Most CAD software programs are based on
standard geometric engines or kernels, and
mainly differ only in terms of their user interface.
Further, the user base of CAD is several millions,
and technical support is relatively easy since
there are a large number of CAD books, trainers,
and other resources. In contrast, casting
simulation software is highly complex, the user
base is tiny, user expectations are high, and
technical support is challenging. As the
awareness and number of casting simulation
users grow, their cost is bound to come down.
38. Should we opt for in-house simulation
facility or outsource to consultants?
In-house simulation facility is usually preferred by
medium and large foundries, who continuously
need to develop new castings, or improve the
quality and yield of many existing castings in
regular product ion. Foundries handl ing
confidential components for aerospace, defence
and other sectors also need to have in-house
simulation facilities. They should have adequate
qualified human resources to design, simulate
and optimize the castings. Small foundries who
do not meet the above criteria can opt for
simulation services offered by consultants.
39. What are the recommended specs of
computer hardware for simulation?
The hardware ranges from laptop and desktop
computers to powerful workstations and
computer clusters. The latter are needed for
simulating coupled physics for complex and
multi-cavity castings. For most castings however,
desktop computers with Intel i5/i7 or equivalent
CPU, 8-16 GB RAM, graphics card, and 100-200
GB of free hard disk space are sufficient for
completing the simulation at reasonable
accuracy within a few hours. Most of the
programs work in 64-bit Windows operating
systems (which allows utilizing more memory),
and support multi-core CPUs (providing better
performance).
40. What is the role and importance of
technical support for casting simulation?
The technical support team is usually responsible
for initial benchmarking (before software
purchase), installation and training (immediately
a f t e r p u r c h a s e ) . T h e y a l s o h a n d l e
troubleshooting in the event of software not
working for any reason, and re-training if any
major upgrades are installed. Since casting
simulation software are technically complex, the
quality and speed of technical support are critical
for successful continued usage and resultant
benefits.
41. Is web or video conferencing suitable
for software training and technical support?
Video conferencing enables multiple training
sessions over a period, which are more effective
than a single long session. It is also very useful for
technical clarifications or troubleshooting advice
at a short notice. There are many free or low-cost
options for web-based video conferencing, if
broad-band Internet is available (at least 1 Mbps).
These allow video, audio, text-chat, and
computer screen sharing, with option for
switching the mouse control between the two
sides. If internet speed is limited, then only screen
sharing option can be used along with a
telephone line for talking.
42. Do we need knowledge of CAD and
FEA to run casting simulation programs?
Older generation simulation programs, especially
those built by customizing a Finite Element
Method code, require a large number of input
parameters to be specified by the users, and this
requires a good knowledge of FEM as well as the
underlying physics. New generation programs
developed with the latest programming
techniques, usually employ better assumptions
and superior user interfaces, making them more
intelligent and intuitive. This reduces the learning
curve, number of user inputs, and time taken.
43. Is prior methoding experience needed
to use simulation software?
For merely running a simulation program, prior
experience in methoding of castings is not
needed. However, such experience is very useful
for correctly interpreting the results of simulation,
matching them with shop-floor observations, and
for improving the methods design before the next
iteration of simulation. Since it takes several
years to gain useful methoding experience, it is
advisable to team up a senior methoding
engineer with a CAD engineer, for effective
utilization of simulation software.
44. How much time does it take to learn
and start using simulation software?
The user interface for various functions, including
inputs and results, can be learnt within one or two
days and practiced over a week. However,
understanding the importance of various
parameters, learning how to interpret different
results, and customizing of software database
can take several weeks to months. This usually
requires comparing the results of different
projects, reading technical literature, and
discussion with experts.
45. How can we reduce the total time for
casting optimization using simulation?
The total time depends on the number of
iterations and time per iteration. The number of
iterations can be reduced by using relevant
knowledge of methoding and prior experience
with similar castings. The time for each iteration
can be reduced by using better computation
hardware (more powerful CPU, higher amount of
computer memory, multi-core and parallel
processing) and using a simulation program that
can leverage the capabilities of high-end
computers.
27
DIFFERENT METHODS OF SG IRON PRODUCTION WITH THEIR
TEHNICAL AND ECONOMICAL ADVANTAGES AND
DISADVANTAGES
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Mr. Mujtaba Ahmad
Foundry Consultant
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