FiLOM
New member
- Jan 23, 2023
- 1
Hi all,
just trying to get into using AISI steels 4130, 4140, 4340, and eventually 1025 and its AMS specifications properly according to MMPDS. Kind of stuck on the "heat treatment" topic. These steals got their mechanical properties specified in MMPDS with a note under the line - "Minimum properties must be substantiated by tensile testing of production material after heat treatment..."
Does it mean that I have to do testing on specimens from the semi-finished product or the finished one?
What I am missing is some notes about machining. About changing the dimensions of material by machining, or about pre-machining and after-machining HT.
E.g. 4340 is supplied in Premium aircraft quality AMS 6414 with UTS 260ksi which is really hard to produce. And I want to machine it. It is machined in that HT260 treatment? What about the residual stresses after machining? Machining may be followed by normalizing, am I right? Than what? Quench and temper it again to HT260? BTW is it even machinable in HT260? Or there has to be pre-machining HT? In that case why even bother HT of semi-product?
And when do I have to do the testing? And from what material in which phase of production do I make the specimen?
just trying to get into using AISI steels 4130, 4140, 4340, and eventually 1025 and its AMS specifications properly according to MMPDS. Kind of stuck on the "heat treatment" topic. These steals got their mechanical properties specified in MMPDS with a note under the line - "Minimum properties must be substantiated by tensile testing of production material after heat treatment..."
Does it mean that I have to do testing on specimens from the semi-finished product or the finished one?
What I am missing is some notes about machining. About changing the dimensions of material by machining, or about pre-machining and after-machining HT.
E.g. 4340 is supplied in Premium aircraft quality AMS 6414 with UTS 260ksi which is really hard to produce. And I want to machine it. It is machined in that HT260 treatment? What about the residual stresses after machining? Machining may be followed by normalizing, am I right? Than what? Quench and temper it again to HT260? BTW is it even machinable in HT260? Or there has to be pre-machining HT? In that case why even bother HT of semi-product?
And when do I have to do the testing? And from what material in which phase of production do I make the specimen?