Growth of Material in Heat Treat
Growth of Material in Heat Treat
(OP)
Does the reduction ratio of the raw material have any bearing on the rate of growth of a part in heat treat? For example, given a single heat of steel, one bar drawn to a diameter of 1" and one bar drawn to a diameter of 1/2". The 1" bar is turned to produce a part of .45" diameter as is the 1/2" bar. Both are heat treated. Would one expect the resulting growth in heat treat to be any different for the two starting sizes of material?





RE: Growth of Material in Heat Treat
RE: Growth of Material in Heat Treat
RE: Growth of Material in Heat Treat
I would recommend that you get the expected expansion
from the manufacturer as different alloys have different rates, some essentially 0.0 others have a negative volume change, others quite high. To stop this growth one has to go to additional steps to to stop growing. Until the advent of LN2 we accomplished this by multiple tempers. If you are going a precision size the transformation has to be complete before finishing.
What material are you working with?
RE: Growth of Material in Heat Treat
I would point out the use of terms such as "should" and "expected" indicating that real-world results may differ from theoretical.
An example we ran into a few years ago involved brazing a carbide ring into a thin steel holder about 6 inches in diameter. Because the steel holder had been machined out of rolled plate it warped a bit during brazing in reflection of its having been rolled.
This was a case where it should have grown and shrunk back to the original shape. But there were other factors at work.
Thomas J. Walz
Carbide Processors, Inc.
www.carbideprocessors.com
Good engineering starts with a Grainger Catalog.
RE: Growth of Material in Heat Treat