Heat Treat Advice - Forgings - 4330V 2

[Macdost]

Hello,

Forgings
Part weight – ~200 lbs
Material - 4330V per AMS 6427

Tensile – 130,000 min
Yield – 109,000 min
Impacts – 55 ft/lbs min @ RT
Hardness – ?

Looking for heat treat advice to meet mechanicals. Impacts and what hardness is what I have no history on.

Thinking quench & temper should suffice, but had input that normalize, Q&T would be in order.

Anyone with prior experience that cares to weigh in I would appreciate it

Thank you

 

[EdStainless]

Often forgings are first normalized because they were not at a uniform temperature during the last stages of forging. The normalize should assist with getting more uniform properties.
What is wrong with standard heat treat guidelines?


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P.E. Metallurgy, Plymouth Tube

 

[Macdost]

Thank you, just worried about the impacts and what hardness to aim for. I cannot find any history on this in our archives.

 

[metengr]

Take a look at this

http://customer.cartech.com/assets/documents/datasheets/4330+V.pdf

 

[redpicker]

Section size is what will be important in developing properties. Also, where are the test specimens to be taken?

Assuming you have no information on the forging temperatures or cooling from forging, normalizing (1750F-1775F) prior to Q&T would be prudent. Those properties are easily achieved with 4330V using an oil quench in sections up to about 4 or 5 inches. Much larger than that, you could run into problems. You'll want to austenitize 1700F prior to quenching to get the vanadium carbides into solution.

A water quench is not advised. If the section is too great to meet properties with an oil quench, consider rough machining prior to heat treatment (but avoid corners or fillets with a radius less than 1/4"). 4330V is somewhat resistant to quench cracking, but it can crack. Cracking can be greatly reduced by not quenching the parts below 250F and not letting the parts cool to below 200F prior to tempering. Polymer quenching is fine, but you'll need to watch the quench exit temperatures.

You will be looking at a hardness range of 262-311 HBW, or so. 262 may be a bit low, but it might be enough; again, it depends on section thickness and test specimen location.

 

[tbuelna]

Here's a data sheet for a Timken alloy similar to 4330V that gives some information for a 150ksi uts condition. Fairly close to what you are looking for.