severity of quench for 5160 or 6150

[metman]

3/8" x 1.5" x 3 material.

Q1) Is water quench too severe for these alloys with this mass and section size?

I intend to recommend tempering to 50-55 HRC because it will act as an impacted cutting blade -- one of three per head -- for primitive manual well drilling in third world countries where used vehicle leaf springs are sometimes the material of choice because of availablility.

I have vol 1 and 2 of ASM hdk 8th edition and cannot find any info on effects of water quenching. Also cannot find recommenced quenchant which apparently is oil based on a bit of googling.

Q2) can someone tell me the Ms and Mf for these two alloys? This is for establishing martempering process which might be possible depending on Ms and Mf even with crude method of heating a couldron of water over a fire but maybe this is getting too technical since the section size is relatively thin so that transformation should occur nearly at the same time at the surface and at full depth.

All thoughts welcome

Design for RELIABILITY, manufacturability, and maintainability

 

[dbooker630]

The ASM Heat Treaters Guide (1995 ed.) recommends oil for both grades and adds polymer for 5160. I have used polymer for quenching stabilizer bars made from 5160.

For 6150 the Guide does not show exact Ms & Mf temperature but looking at the isothermal transformation diagram it looks like the Ms is around 550F, M50 around 490F, and M90 around 450F. The diagram for 5160 shows the Ms to be around 480F and the M50 around 340F.

 

[metman]

Thanks dbooker630,

Boiling water won't be above the Ms in any event.

So back to my original question, i.e. Is water quench too severe for these alloys with this mass and section size?

I understand the problem of severe quench in a thick section but what about 3/8" thick?


Design for RELIABILITY, manufacturability, and maintainability

 

[CoryPad]

Water is a severe quench for these alloys and you can expect cracking.

 

[arunmrao]

From my experience, water quenching is severe resulting in cracking. Polymer quench or better still,oil is recommended. You could go home peacefully and sleep, while the heat treatment is in progress.Else, it becomes a nightmare!

 

[metman]

Thanks for the advice which is well received.

Design for RELIABILITY, manufacturability, and maintainability