How much machining can 410SS take before it starts to change

[merkyworks]

A machine shop ordered the wrong size material and I'm trying to find some information on what the effects of machining material very heavily are.

Material is 410 SS in the quenched and double tempered condition for NACE service, HRC 22 max/BHN 207-235. Bar stock is 5" dia and will have to be machined down to 3.47" dia. I'm worried about the effects of removing this much material and how it will effect the strength/structure of the 410SS.

any info on this would be great!

 

[Metalguy]

410 is a very deep hardening stainless, so it should be hardened right to the core. I don't think there will be a problem.

"You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein

 

[mw1st]

410 SS, actually all martensitic grades have extremely high hardenability compering with carbon or alloy steel. If you look at end-quench hardenability line for 410, the end that was quenched in water is no harder than opposite end which was cooled in still air. Like Metalguy stated, you should have no problem.

 

[blacksmith37]

However; heavy metal removal can leave "submicroscopic" cold work which can reduce resistance to hydrogen stress cracking- if in a severe sulfide/hydrogen environment. I suggest taking off the last 0.050" at < 0.005" per cut.
The only alloys in which I have seen this effect were Cr:Mo low alloy.

 

[remetaper]

The main problem could be a bending of bar during the machining or after this one even if the previous double tempering could reduce this behaviour that - however- will depend on the lenght of bar. Merkyworks, I agree with Metalguy but also what Blacksmith37 could be evaluated if you consider the large "stock removing " ( 50% +/-).
However, if you wanted to avoid any kind of troulble ,you could stress relieve the bar after the last step of machining.Obviously,if bar were bended, you have to straight and ,then, stress relieve. Temperature of stress relieving has to be 25°C under the tempering temperature. If this temperature weren't shown in certificate, the Supplier of steel must kindly declare.