Different material?

[limct]

Hi there,
I was told by my supplier that the below samples A & B are of the same material JIS SCM415 (Chrome Molydenum Steel), I really have my doubt. Can anyone advise.
Below id the hardness data (HV 0.3)
depth A B
0.05 762 738
0.1 746 744
0.2 645 755
0.3 532 758
0.4 463 712
0.5 438 684
0.6 420 644
0.7 410 621
0.8 405 570
0.9 400 527
core 385 516

According to them, both samples are different by the heat treatment process. But I really doubt that with 0.15% C, the core hardness can go up to >500 HV.


Best regards,
ct

 

[Goahead]

Hi,
you are probably right.
Why not asking the supplier to get you
an independent chemical analysis just of C,
or an X-Ray fluorescence test of both samples?
The answer should settle the question.
Mix up of materials can occur.
Regards,

http://www.welding-advisers.com/

 

[TVP]

Were the components carburized? SCM415 is often used for carburizing, and the hardness values that you indicated are typical for a carburized part. Depending on the C potential and the treatment time, a hardness of > 500 HV at 1 mm can definitely be achieved in SCM415. How far below the surface was the "core" measurement taken? Have you etched the cross-section to see the affected zone?

 

[limct]

Both parst were carburised.
But I think I gotta go for chemical analysis, that would give me the answer right away.
I agree that 500HV is achievable by SCM415, but to control the part to this extent doesn't seem to be practical, at least from economic stand point.


Best regards,
ct