Welding Engineers’ Toolkit - NSRP · • Naval Welding Engineers’ Toolkit developed and maintained by NSWC Carderock – Computational reference tool ... AWS Welding Handbook

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

Development of the Naval

Welding Engineers’ Toolkit

(NAVWET)

National Shipbuilding Research Program

Welding Technology Panel Meeting

March 9, 2017

Daniel Bechetti

Welding, Processing, and NDE Branch

Naval Surface Warfare Center, Carderock Division


Overview

• Background

– Naval engineers routinely perform a variety of welding-related

calculations to develop welding procedures and testing plans

– Software to perform some of these calculations exists but requires

paid licenses and computer compatibility

– Many of these calculations are made using spreadsheets designed

and maintained by individual engineers

• Objectives

– To develop a suite of calculators for naval welding-related

problems, standardize routine calculations, and acquire reasonable

estimates for more complex calculations

– To build/provide this suite in a ubiquitous software platform so

that it can be easily distributed and updated

– To provide technical references wherever possible so that

calculation methods are clear and can be explored further if desired

NavWeld (Weld QC)

SmartWeld (Sandia National Labs)

2

Examples of currently available software:


NAVWET

• Naval Welding Engineers’ Toolkit

developed and maintained by NSWC

Carderock

– Computational reference tool

– Built in and run from MS Excel

– Current version contains three ‘modules’ that

perform groups of related calculations

– Technical references provided wherever possible

and detailed descriptions of the calculation

methods and assumptions provided

– All relevant data stored within the spreadsheet

3


Module 1: Preheat Determination

Purpose:

• To provide reference compositions of typical Naval steels

• To provide a standard calculator for carbon equivalent

• To provide base metal and filler metal preheat and interpass

requirements for S-1, S-2, and S-11 materials as outlined in Tech.

Pub. 1688, Rev. 1

Inputs:

• Base materials

Method:

• Cross-references user inputs with composition database

Outputs:

• Reference nominal compositions for 175 base material and filler

materials variants

4



Purpose:





Pub. 1688, Rev. 1

Inputs:

• Base materials

• Filler material

Method:


Outputs:


materials variants

5



Purpose:





Pub. 1688, Rev. 1

Inputs:

• Base materials

• Filler material

• Carbon equivalent method

Method:


Outputs:


materials variants

• Carbon equivalent values from the user’s choice of 8 calculation

methods

6



Purpose:





Pub. 1688, Rev. 1

Inputs:

• Base materials

• Filler material

• Carbon equivalent method

• Thickness

• Welding Process

Method:

• Cross-references user inputs with composition database and

preheat tables, including footnotes

Outputs:


materials variants

• Carbon equivalent values from the user’s choice of 8 calculation

methods

• Itemized preheat and interpass requirements for the selected base

and filler metals

7


Module 2: Thermal Behavior

Purpose:

• To provide reasonable estimates of fusion zone cooling rate,

weld pool size, heat affected zone (HAZ) size, HAZ thermal

cycle, and coarse grained HAZ cooling time

Inputs:

• Welding parameters or heat input

Method:

• Fusion zone cooling rate – calculation process described in

AWS Welding Handbook and ASM Materials Handbook

Example Outputs:

1. Cooling rate of weld metal at the chosen temperature, with

tabulation for comparisons

8


Module 2: Thermal Behavior (Cont.)

Purpose:




Inputs:


Method:



• Time-temperature data – Rosenthal model for 2-D and 3-D

heat flow

Example Outputs:



2. Automatic plotting of steady-state isotherms at chosen

temperatures

9

FZ

FGHAZ

HAZ Edge


Purpose:




Inputs:


Method:




heat flow

Example Outputs:




temperatures

3. HAZ thermal cycle for chosen distance from weld

centerline, with optional overlay on CCT diagram

10



Purpose:




Inputs:


Method:




heat flow

Example Outputs:




temperatures



11



Purpose:




Inputs:


Method:




heat flow

Example Outputs:




temperatures



4. Cooling time from 800°C to 500°C

12



Module 3: Dilution in Overlays

Purpose:

• To calculate the amount of dilution (base metal mixing) in

a weld overlay or cladding

• To calculate the composition of an arbitrary layer in the

overlay or cladding

Inputs:

• Substrate and overlay material class

• Welding parameters

Method:

• Thermodynamic data calculated using ThermoCalc

• Dilution percentage determined using the method

described by DuPont and Marder

Outputs:

• Dilution percentage

13


Module 3: Dilution in Overlays

Purpose:

• To calculate the amount of dilution (base metal mixing) in

a weld overlay or cladding

• To calculate the composition of an arbitrary layer in the

overlay or cladding

Inputs:

• Substrate and overlay material class

• Welding parameters

Method:

• Thermodynamic data calculated using ThermoCalc

• Dilution percentage determined using the method

described by DuPont and Marder

• Composition calculations performed using bead-on-plate

welding equations, assumptions made for layers other

than the first

Outputs:

• Dilution percentage

• Deposited weld metal composition for a chosen layer

14


Future Plans

• Fillet weld sizing and design

- To organize and simplify the many possible weld computation factors described in MIL-STD-1628A

• Weld metal constitution diagrams

- For prediction of weld metal solidification mode in similar and dissimilar welds

• Experimental validation of some current calculations to validate assumptions

• Distribution to warfare centers and public shipyards in CY17 for initial testing, user feedback, and

refinement

15

WRC-1992 constitution diagram

Fillet weld computational factors from MIL-STD-1628A


Questions?

This work was funded by NSWC Carderock Division under the Naval Innovative

Science and Engineering (NISE) NDAA Section 219 program, managed by the NSWC

Carderock Division Director of Research

The software presented herein is intended as a reference, estimation, and comparison

tool. It is incumbent upon individual users to verify conformance of outputs to NAVSEA

directives. No liability is assumed by NAVSEA, NSWCCD, or their employees regarding

the use, output, or application of this software.

Acknowledgements

Documents

Welding Engineers’ Toolkit - NSRP · • Naval Welding Engineers’ Toolkit developed and maintained by NSWC Carderock – Computational reference tool ... AWS Welding Handbook