Work Hardening During Machining 2

[saberblue]

Is there some way that I can predict from the chemistry of a steel how badly it will work harden when it is ground and or machined?

 

[mcguire]

yes, you can. But, it isn't simple. If you say which alloy types you are working with, we can tell you how the pertinent elements affect work hardening. But you need to be specific because comparisons from one alloy to another can be very misleading.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[saberblue]

My problem is that we make metal working fluids and we see every thing under the sun. The selection and aplication of the fluid can make a major difference in how much work hardening takes place but to get a reduction in amount of rubbing that takes place you have to trade off something else.

So what I am looking for is some way of quntifying the amount of work hardening even if that is no more sustifacted than - yes, maybe, and no.

 

[TVP]

I have several thoughts right off the top of my head:

1. This can become complicated in alloys where transformations take place (martensite formation, overtempering of previously Q&T steels, etc.).

2. If all you need is quantification, then measuring microhardness on a cross-sectioned piece will be easier than trying to predict based on chemistry.

3. Predicting based on chemistry will require knowledge of the microstructure as well, since this is have as much of an effect if not more.

 

[saberblue]

If we assume that my usual customer is the machine shop forman in a shop that has no chemical or metalergical lab and it is. How as a practical maner do I get micro hardness?

Is there some way we can look it up even if it is just a range?

Thanks for the assist. this one has been bugging me for some time. Anything you can contribute is helpfull

 

[mcguire]

Any metal you customer has purchased should have a certification with tensile test results. Take the difference between the yield strength and tensile strength and divide by the elongation. This number is the linear approximation of the work hardening rate.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[saberblue]

Great that I can do!!


I can probalby even develop a table of typical values for "standard" materials using MatWeb for my sales and applications guys.

Looking forward to yor book!