thread367-313448 hi Guys we

[confused21]

thread367-313448

hi Guys

we have had tensile reults for ASTM A148 GR130-115.
the parts were quench and tempered, but failed.
is there a recommended heat treatment for this please.
the results for .2% were 670, spec requires 795 and tesiles were 726, spec requires 895.

these were heat treated at 920 2 hour water quench and the 4 hours at 640 then water quench.

i would be very greatful for any help please.

thanks

 

[mrfailure]

Looks like what you really have is Grade 725-585 (i.e 105-85). If this came from a supplier, then the material was misrepresented. If you made it, then you need to review what A148 calls out (I don't have a copy of it so I can't comment there), and you also need to review and modify your austenitization (hardening) and tempering processes to meet the tensile and yield requirements.

 

[Tmoose]

"the parts were quench and tempered, but failed."

UTS, yield, elongation or ??

 

[mrfailure]

Tmoose: lakk gave the grade UTS and yield requirements asking the initial question. Elongation was not discussed.

 

[confused21]

hi all

the elongation was 18%, the requirement was 11%.
its the .2 and tensiles we are having trouble with.

 

[bobjustbob]

ASTM A148 does not give a particular chemistry just some max P and S, unless it has changed since I last worked with it. What steel grade are you pouring? C, Mn, Ni, Cr and Mo would be helpful. What size test coupons are you cutting your samples from? I assume you are breaking standard .505 rounds correct? What is your as quenched hardness? Without more information it is difficult to make a good recommendation besides just lower your temper temperature. Or you could just temper at 1000°F and see what happens.

Bob