The bands of segregation and where the cracks are forming have high Rc harness 57-58 after draw, could this lead to the grinder causing the cracks? I want to increase draw time to get the low end of the spec for hardness.
thanks swall, that is what i have been trying to do here, i have increased the quench temp to "soften" the quench so far this has not helped. There is only a second delay after heat treat to quench, should i lenghthen that time?
Hey Fred, yeah these are opening up to where you can see it visually, it has fooled me before too but i know now what to look for, we did cut one up and cracks are present
there are some evidence of sulfide inclusions that we may be opening up at heat treat. Can we do anything to lessen the effects of these inclusions when he induction harden and quench?
we have mag'd some after rough machining and saw some evidence of inclusions but not any cracks. It is sporadic on about 20-25 % of the parts. Thanks for the info on the trim dies.
First off thanks guys for everybodys responses, Everybody has great input. The part is forged, it is rough machined before induction hardening. The part is a crankshaft so induction hardening of the main journals is the process used. We are only seeing the cracks directly in the middle of...
550 F The Time always depends on the 3rd shift operator can be as long as 4-5 hours before the first part hardened gets to the draw oven. About 50 Rc after draw. Thanks for your help guys
hello all, I am having a problem of cracking in 4140. I am induction hardening and tempering. I am having small crack develop along the parting line showing up under magnaflux. The draw temperature is 550 for 2 hours. Is temper embrittlement any issue? I am racking my brain on why we are...
