9cr-1Mo steel properties

[asvipin]

What is the difference between ASTM A387 grade 9 class 1 and class 2. Is it only in tensile properties? Class 2 is having higher tensile strength, does that mean it is having finer grains and less creep strength(Operating temperature 500 C) compared to class 1?
Thanks in advance

 

[metengr]

Yes, it is the minimum tensile properties below from Tables 2 and 3 based on heat treatment specified.


Class 1 60-85 Ksi UTS, 30 Ksi YS
Class 2 75-100 Ksi UTS, 45 Ksi YS

 

[EdStainless]

I would suggest that you look at ASME SA387, and then look in Sec II at the allowed stress at various temperatures.
This will answer your question.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[metengr]

The creep strength of Class 2 is no different from Class 1 at or above 900 deg F. Both alloys respond the same to time dependent behavior (creep or stress rupture), which is why tensile properties govern below
900 deg F.

 

[asvipin]

Thanks for reply.