1.1
(Heat treatment) . , () . :a-
b- .
c- .1.2
1.2.1
. (1)
a- , (1-b) , . . 150 1250 b- () () . . . (2) .
1.2.2
a-
.
. , . 250 1600 . 600 3000 . (3)
b-
, (4-a), , (4-b), (4-c). () (1371 - 37.8 ) . .
1.2.3
, , , , .
a-
() . .
b-
, . .c -
.
d-
, .
1.3
, . (1) , . (1)
(steel colours at various temperature with their related processes)
1.4 () (% 0.35) , . , . (5) .1.4.1
((Carbon Content
((Hardening Temperature Range
% 0.80 0.65% 0.95 0.80% 1.1 0.95 % 1.1
(1550 1450) F C (843 - 788)
(1460 1410) F C (739 - 766)
(1450 1400) F C (788 - 760)
(1430 1380) F C (777 - 749)
(2) . 27.8 55.6 .1.4.2
:
a- C (871 - 715) .b- c- . . , . .1.5 . , ( ) .:
:
a- .b- (3) .c- . (3)
FC
Scribers
Center punches
Cold chisels
Screwdrivers
450 430
470
510 480
530230 220
243
265 255
270
1.6 () (annealing) .1.6.1 :
a- .
b- .
c- .1.6.2
:a- (56 - 28) (A3) , (6).
b- . , (25 mm) .c- (28) C (A 1).
d- .
1.6.3 . (A1) . , .1.7 (normalizing) , .:
:
a- (56)C ( A3), .(8)
b- .c- .1.8
. .:
a- , (A1) , (9)
b- .
c- .
1.9 (Case hardening) , () , (10)
a- , (915 - 745) (5.11). . ( 4 6 ) . . .
b-
, . , .c-
. . . .1.10 . .a - . (12)
b-
() . (), (13) . .
1.11 a-
1- () : . 420 300 , ( ) . O2- : 450 540 , . , 4 5 (TB)b- 600 . .c- () .
colours
A3 : Upper critical temperature
A1: Lower critical temperature
(8) (Normalising)
A3 : Upper critical temperature
A1: Lower critical temperature
(7) (Annealing)
A3 : Upper critical temperature
A1: Lower critical temperature
(9) (thermal stress relieving)
(1) ((Heating furnaces
UNION ENGINEERING GROUP
Egyptian Welding Academy
TECHNICAL CENTER
(2)
(3) (optical pyrometer)
a- b- c-
(4) Temperature indicating products))
Celsius / Fahrenheit
Processes
1370 2500
1315 2400
1259 2300
648 1200
1204 2200
1036 1900
1149 2100
1093 2000
981 1800
926 1700
871 1600
760 1400
815 1500
538 1000
704 1300
593 1100
426 800
371 700
315 600
260 500
204 400
93 200
149 300
482 900
38 100
18 0
High speed steel hardening
11931343c
(2150 - 2450 F)
Welding
Alloy tool steel hardening
815 - 1065 C
(1500 - 1950 F)
Carbon Tool Steel Hardening
732 - 843 C
(1350 - 1550 F)
High Speed steel Tempering
815 - 1065 C
(1500 - 1950 F)
Carbon Tool steel Tempering
149 - 565 C
(300 - 1050 F)
Heat Colours
Temper
Colours
White
Yellow White
Yellow
Orange Red
Light Cherry Red
Cherry Red
Dark Red
Very Dark Red
Black Red
In dull light or Darkness
Pale Blue 310 C ( 590 F)
Violet 285 C ( 545 F)
Purple 274 C ( 525 F)
Yellowish Brown 310 C ( 590 F)
Dark Straw 241 C ( 465 F)
Light Straw 218 C ( 425 F)
(5) (Iron Carbon Diagram)
1- (Hardened outer case or shell)
2- (Interior remains relatively soft and tough)
(10) (Case hardening)
(11) (Part packed in container of carbonaceous material)
(12)
1 - (Induced eddy current)
2- (Magnetic Field)
3- (Heat produced by eddy current)
(13)
(Heating surface of steel shaft with high frequency induction coil