Critical point of common steel
Grade |
Critical point / ℃ |
|||
Ac1 |
Ac3 or Accm |
Ar1 |
Ar3 |
|
10 |
725 |
870 |
682 |
850 |
10Mn2A |
720 |
830 |
620 |
714 |
12CrNi3A |
695 |
800 |
659 |
726 |
100CrNi3A |
680 |
– |
– |
– |
12Cr2Ni4A |
670 |
780 |
575 |
660 |
100Cr2Ni4A |
670 |
– |
– |
– |
15 |
725 |
870 |
685 |
850 |
15Mn |
735 |
863 |
685 |
840 |
15SiMn2MoVA |
722 |
848 |
491 |
– |
15Cr |
735 |
870 |
720 |
– |
15CrMnA |
750 |
848 |
– |
– |
15CrMnMoVA |
765 |
870 |
– |
– |
18Mn2CrMoB |
741 |
854 |
– |
– |
18Cr2Ni4WA |
655~695 |
– |
– |
– |
20 |
735 |
855 |
680 |
835 |
20Mn |
735 |
854 |
682 |
835 |
20Mn2 |
690 |
820 |
(610) |
(760) |
20Mn2B |
730 |
835 |
613 |
730 |
20MnVB |
720 |
840 |
635 |
770 |
20MnTiB |
(720) |
843 |
625 |
795 |
20MnMoB |
738 |
850 |
693 |
750 |
20Cr |
766 |
838 |
702 |
799 |
20CrV |
768 |
840 |
704 |
782 |
20CrMnB |
– |
890 |
622 |
749 |
20CrNi |
735 |
805 |
660 |
790 |
20CrNi3A |
710 |
790 |
– |
– |
20Cr2Ni4A |
705 |
770 |
575 |
660 |
22CrMnMo |
710 |
830 |
620 |
740 |
30 |
732 |
813 |
677 |
796 |
30Mn2 |
718 |
804 |
627 |
727 |
30Mn |
734 |
812 |
675 |
796 |
30SiMnMoV |
740 |
845 |
– |
– |
30Si2Mn2MoWV |
739 |
798 |
– |
– |
30CrMnSi |
760 |
830 |
670 |
705 |
30CrMo |
757 |
807 |
693 |
763 |
30CrMnTi |
765 |
790 |
500 |
740 |
30CrMnSiNi2A |
750~760 |
805~830 |
– |
– |
30CrNi3 |
705 |
750 |
– |
– |
35SiMn |
750 |
830 |
645 |
– |
35CrMoV |
755 |
835 |
600 |
– |
35CrMo |
755 |
800 |
695 |
750 |
35CrMnSi |
760 |
830 |
670 |
705 |
38Cr |
740 |
780 |
693 |
730 |
38CrMoAl |
800 |
840 |
730 |
– |
37CrNi3 |
710 |
770 |
640 |
– |
38CrSi |
763 |
810 |
680 |
755 |
40 |
724 |
790 |
680 |
760 |
40Mn |
726 |
790 |
689 |
768 |
40Mn2 |
713 |
766 |
627 |
704 |
40MnB |
730 |
780 |
650 |
700 |
40MnVB |
730 |
774 |
639 |
681 |
40Cr |
743 |
782 |
693 |
730 |
40CrV |
755 |
790 |
700 |
745 |
40CrMnMo |
735 |
780 |
680 |
– |
40CrSi |
755 |
850 |
– |
– |
40CrMnSiMoV |
780 |
830 |
– |
– |
40CrMnSiMoVRe |
725 |
850 |
625 |
715 |
40Cr 5M02VSi |
853 |
915 |
720 |
830 |
40SiMnMoVRe |
765 |
900 |
625 |
730 |
40CrNi |
731 |
769 |
660 |
702 |
40CrNiMo |
710 |
790 |
– |
– |
40CrMo |
730 |
780 |
– |
– |
45 |
724 |
780 |
682 |
751 |
45Mn2 |
715 |
770 |
640 |
720 |
45Mn2V |
725 |
770 |
– |
– |
45Cr |
721 |
771 |
660 |
693 |
50 |
720 |
765 |
690 |
720 |
50Mn |
720 |
760 |
660 |
– |
50Mn2 |
710 |
760 |
596 |
680 |
50Cr |
721 |
771 |
660 |
692 |
50CrV |
752 |
788 |
688 |
746 |
50CrMn |
750 |
775 |
– |
– |
55 |
727 |
774 |
690 |
755 |
55Si2Mn |
775 |
840 |
– |
– |
55Si2MnB |
764 |
794 |
– |
– |
55Si2MnVB |
765 |
803 |
– |
– |
60 |
727 |
766 |
690 |
743 |
60Mn |
727 |
765 |
689 |
741 |
60Si2Mn |
755 |
810 |
700 |
770 |
65 |
727 |
752 |
696 |
730 |
65Mn |
726 |
765 |
689 |
741 |
70 |
730 |
743 |
693 |
727 |
85 |
723 |
737 |
– |
695 |
T7 |
730 |
770 |
700 |
– |
T8 |
730 |
– |
700 |
– |
T10 |
730 |
800 |
700 |
– |
T11 |
730 |
810 |
700 |
– |
T12 |
730 |
820 |
700 |
– |
SiMn |
760 |
865 |
708 |
– |
9SiCr |
770 |
870 |
730 |
– |
CrWMn |
750 |
940 |
710 |
– |
3Cr2W8V |
820 |
1100 |
790 |
– |
3Cr2W8 |
810 |
1100 |
– |
– |
W18Cr4V |
820 |
1330 |
760 |
– |
W9Cr4V2 |
810 |
– |
760 |
– |
3Cr 3Mo 3VNb |
836~948 |
– |
771~923 |
– |
Cr12V |
810 |
– |
760 |
– |
Cr12MoV |
815 |
– |
– |
– |
Cr 12Mo |
810 |
1200 |
760 |
– |
5C rMnMo |
710 |
760 |
650 |
– |
5CrNiMo |
710 |
770 |
680 |
– |
GCr15 |
745 |
900 |
700 |
– |
GCr15SiMn |
770 |
872 |
708 |
– |
1Cr13 |
730 |
850 |
700 |
820 |
2Cr13 |
820 |
950 |
780 |
– |
3Cr13 |
780~850 |
– |
– |
– |
4Cr13 |
790~850 |
– |
– |
– |
Cr17Ni2 |
810 |
– |
710 |
– |
9Cr18 |
830 |
– |
810 |
– |
4Cr9Si2 |
900 |
970 |
810 |
870 |
4Cr10Si2Mo |
850 |
950 |
700 |
845 |
Mn13 |
– |
– |
– |
– |
Quenching heating temperature and Ms point of common steel
Grade |
Quenching heating temperature (℃) |
Ms/℃ |
10 |
900~920(water)or no heat treatment |
450 |
10Mn2A |
850~857(water) |
– |
12CrNi3A |
860(oil) 780~810(oil) |
(420) |
100CrNi3A |
860(oil) 780~810(oil) |
150 |
12Cr2Ni4A |
860(oil) 780(oil) |
400 |
100Cr2Ni4A |
880(oil) 780(oil) |
125 |
15 |
890~920(water) |
450 |
15Mn |
850~900(water) |
410 |
15SiMn2MoVA |
880(oil) |
275 |
15Cr |
860(oil) 780~810(oil) |
– |
15CrMnA |
840~870(oil) 810~840(oil) |
400 |
15CrMnMoVA |
965~985(air or oil) |
372 |
18Mn2CrMoB |
920(air or oil) |
320 |
18Cr2Ni4WA |
950(air) 860~870(oil) |
310 |
100Cr2Ni4WA |
– |
75 |
20 |
900~950(water) |
425 |
20Mn |
850~900(water) |
(420) |
20Mn2 |
860~880(water) 880~910(oil) |
370 |
20Mn2B |
860~880(oil) |
– |
20MnVB |
860~880(oil) |
230 |
20MnTiB |
860~890(oil) |
– |
20MnMoB |
850~890 (oil) |
– |
20Cr |
860~880(oil) |
(390) |
20CrV |
870~900(oil) |
– |
20CrMnB |
860~880(water or oil) |
– |
20CrNi |
840~880(water or oil) |
(410) |
20CrNi3A |
820~-840(oil) |
(340) |
20Cr2Ni4A |
(330) |
|
22CrMnMo |
830~850(oil) |
– |
30 |
850~890(water or oil) |
380 |
30Mn2 |
820~840(water) 830~850(oil) |
340 |
30Mn |
850~900(oil) |
355 |
30SiMnMoV |
850~890(oil) |
|
30Si2Mn2MoWV |
950(oil) |
310 |
30CrMnSi |
870~890(oil) |
320 |
30CrMo |
850~880(water or oil) |
345 |
30CrMnTi |
870~890(oil) |
– |
30CrMnSiNi2A |
890~900(oil) |
314 |
30CrNi3 |
830(oil) |
305 |
35SiMn |
880~900(oil) |
(330) |
35CrMoV |
900~920(water or oil) |
– |
35CrMo |
820~840(water) 830~850(oil) |
271 |
35CrMnSi |
850~870(oil) |
– |
38Cr |
860(oil) |
250 |
38CrMoAl |
930~950(oil) |
(370) |
37CrNi3 |
820(oil) |
(280) |
38CrSi |
900~920(water or oil) |
(330) |
40 |
830~880(water or oil) |
(340) |
40Mn |
820~860(water or oil) |
– |
40Mn2 |
810~850(oil) |
(340) |
40MnB |
820~860(oil) |
– |
40MnVB |
830~870(oil) |
– |
40Cr |
830~860(oil) |
(355) |
40CrV |
880(oil) |
218 |
40CrMnMo |
840~860(oil) |
– |
40CrSi |
900~920(water or oil) |
(320) |
40CrMnSiMoV |
920 (oil) |
290 |
40CrMnSiMoVRe |
930 (oil) |
270 |
40Cr 5M02VSi |
1000(air) |
325 |
40SiMnMoVRe |
930 (oil) |
300~305 |
40CrNi |
820~840 |
271 |
40CrNiMo |
850(oil) |
320 |
40CrMo |
820~840(water) |
360 |
45 |
780~860(water or oil) |
(345) |
45Mn2 |
810~840(oil) |
320 |
45Mn2V |
840-860 (water) |
310 |
45Cr |
820 ~ -840 (oil) |
(355) |
50 |
820~850 (water or oil) |
(320) |
50Mn |
780 ~ 840 (water or oil) |
320 |
50Mn2 |
810-840 (oil) |
325 |
50Cr |
820 (oil) |
250 |
50CrV |
860 (oil) |
(270) |
50CrMn |
840~860 (oil) |
(250) |
55 |
790~830(water) 820~850 (oil) |
(290) |
55Si2Mn |
850~880(water or oil) |
(280) |
55Si2MnB |
870(oil) |
– |
55Si2MnVB |
880(oil) |
– |
60 |
780~830(water or oil) |
270 |
60Mn |
790~820(oil or 160℃nitrate) |
270 |
60Si2Mn |
840~860(water or oil) |
305 |
65 |
780~830(water or oil) |
270 |
65Mn |
790-820(oil or 160℃nitrate) |
270 |
70 |
780~830(water or oil) |
230 |
85 |
780~820(water or oil) |
220 |
T7 |
800~820(water) |
250~300 |
T8 |
780~820(water) |
225~250 |
T10 |
770~790(water) |
175~210 |
T11 |
770~790(water) |
200 |
T12 |
770~790(water) |
– |
SiMn |
780~840(water, oil or nitrate) |
(250) |
9SiCr |
860~870(oil) |
(170) |
CrWMn |
800~830(oil) |
(250) |
3Cr2W8V |
1050~1100(oil) |
(340) |
3Cr2W8 |
1075~1130(oil) |
330 |
W18Cr4V |
1280~1300(oil) |
(220) |
W9Cr4V2 |
1225~1240(oil) |
(200) |
3Cr 3Mo 3VNb |
1060~1090(oil) |
385 |
Cr12V |
1040~1080(oil) |
180 |
Cr12MoV |
1040~1050 1120~1130(air or) |
(<185) |
Cr 12Mo |
950~1000(oil) |
(225) |
5C rMnMo |
820~850(oil) |
(220) |
5CrNiMo |
830~860(oil) |
(220) |
GCr15 |
820~850(oil) |
(240) |
GCr15SiMn |
820~840(oil) |
– |
1Cr13 |
980~1050(oil) |
(350) |
2Cr13 |
980~1050(oil) |
320 |
3Cr13 |
980~1050(oil) |
(240) |
4Cr13 |
980~1050(oil) |
145~270 |
Cr17Ni2 |
950~970(oil) |
357 |
9Cr18 |
1050~1075(oil) |
– |
4Cr9Si2 |
1000~1050(oil) |
– |
4Cr10Si2Mo |
1010~1050(oil or air) |
– |
Mn13 |
1050(oil or water) |
200 |
Note: the data in brackets in the table need further study because:
1. Different data provide different data for the same steel type, but only one is selected in this table:
2. The data of the same steel type is gathered from different data.