28
SURFACE HARDENING HEAVY CROSS SECTION - IMPOSSIBLE TO COOL QUICKLY TO PRODUCE A UNIFORMLY MARTENSITIC STRUCTURE THROUGHOUT A SOFT UNHARDENED CORE DUE TO RELATIVELY SLOW COOLING RATE. CORE WITH FINE PEARLITE, SURFACE MARTENSITIC- CALLED MASS EFFECT OF HEAT TREATMENT 0.1% C TOUGH & SOFT; 0.8% C HARD & BRITTLE CERTAIN APPLICATIONS WHERE CORE AND SURFACE SHALL HAVE DIFFERENT PROPERTIES. Eg: Cam, Gears, Shafts to have hard and wear resistant surfaces, but TOUGH, shock resistant cores HARDNESS- TOUGHNESS- MALLEABILITY- [COMPRESSION ](eg: rolling, forging)- DUCTILITY- [TENSION ](eg: wires drawn)

Surface Hardening Processes

Embed Size (px)

DESCRIPTION

hardenin surface

Citation preview

SURFACE HARDENINGHEAVY CROSS SECTION - IMPOSSIBLE TO COOL QUICKLY TO PRODUCE A UNIFORMLY MARTENSITIC STRUCTURE THROUGHOUTA SOFT UNHARDENED CORE DUE TO RELATIVELY SLOW COOLING RATE.CORE WITH FINE PEARLITE, SURFACE MARTENSITIC- CALLEDMASS EFFECT OF HEAT TREATMENT 0.1% C TOUGH & SOFT; 0.8% C HARD & BRITTLECERTAIN APPLICATIONS WHERE CORE AND SURFACE SHALL HAVE DIFFERENT PROPERTIES.Eg:C!" G#$%" S&'(% () &*# &$+ ,+ -#$ $#%.%(,( %/$'0#%" 1/( TOUGH" %&)02 $#%.%(,( 0)$#% HARDNESS3TOUGHNESS3 MALLEABILITY34COMPRESSION 56#g: $)77.,g" ')$g.,g83 DUCTILITY3 4TENSION 56#g: -.$#% +$-,8C$1), )$ N.($)g#, to penet!te to "o#e $ept% &o %!$ne"" to 'n(e!"e on ")&!(eF7!# )$ I,+/0(.), &$+#,.,g &o *o(!*'"e$ p)po"e"CASE HARDENING e+; Wo)+%t Ion to "tee* ,- Ce#ent!t'on C!,on $'&&)"e$ 'nto Ion .o& Fe9C "t)(t)e/CASE HAR0ENIN1S)7.+"L.:/.+ )$G%#)/% #e$')#R#7#%# 0$1), ( %/$'0# " 1%)$1 .,(#$%(.(.77; () %(##73 B; DIFFUSION DEPTH DERIVED BY SECOND LAWFICK ,). )' !)7#% )' B ()!% 0$)%%.,g ?#$ /,.( (.!#D> D.''/%.), 0)#''.0.#,(A> P7,$ $#+0=+@> 0),0#,($(.), g$+.#,(I' A > '7/@ '7)- = /,.( $# ?#$ /,.( (.!#" PACK CARBURISING P02.,g -)$2 ., BC C$" B0 N. ( $#%.%(.,g %(##7 1)@#%-.(& C0 !! g?-.(& 0$1/$.%.,g !(#$.7.H#(#+ %7)-7; () DC0 E FBC0 C" !.,(.,#+ ')$ D &$% 00)$+.,g () +#?(& ,##+#+.Te#pe!t)eC

$1/$.%.,g T.!#D#?(& )' 0%#CHARCOAL WITH BARIUM CARBONATE AS ENERGISER 610 () 1C%8. P$)0#%% +#?#,+% ), ?$#%#,0# )' CO BC G O B B CO A( %/$'0#" $#7#%#% C ()!% BCOCOB G CC +.%%)7*#+ .,(#$%(.(.77; ( %/$'0# )' %(##7. B CO9B O G COB COB G C BCO LI2UI0 3ATHM'4t)e o& "!*t" o& So$')# C-!n'$e, So$')# (!,on!te, So$')#5,!')# C%*o'$eMe*te$ 'n pot" to 860- 7800 C, 9o: '##e"e$ &o 8 #'n to ; %o)T%en ,!":et ;GA p*)+-List of Parts;- F/%# H)7+#$B3 C)*#$ S0$#-93 E$(& P.,H3 W.$# '.@.,g %0$#-C3 L.*# ,+ N#/($7 P.,%O3 F/%# &)7+#$ $.*#(CLADDINGM!'n*- 'n t%e #!n)&!(t)e o& (*!$ "%eet"- e#p*o-e$ p'o to t%e &'n!* #!n)&!(t)'n+ "t!+e" o& ! (o#ponent3!"e #et!* "!n$9'(%e$ ,et9een t%e p'e(e" o& t%e (o!t'n+ #et!*, "!n$9'(% t%en o**e$ to t%e e