Manufacturing

Two Problems here that need addressing,

1 Rust. The material will rust readily for numerous reasons;

• exposure to high humidity, moisture, water, or a chemical environment. Consider storage, transport conditions.
• any molecular modification of the metal due to excessive heat from cutting, or machining. How is it being machined, and cut?

2. Damages. Damages invariably are caused by rough handling. Consider having the pieces mounted on something that stops them from colliding with each other during the annealing and transport processes. i.e if these are the unassembled plates of an armature, mount them on a pipe or rod. This can be done on completion of the machining or cutting.

The rod(s) should be the correct size to fit in the annealer. You may be able to have a setup with numerous rods. You will find that stacking the plates like this, you will actually be able to get more in the annealer then just loose in a container.

Why are you annealing this grade?

IT is equal to US 1215, very low carbon. You are wasting time money energy. trying to change an "EMPTY" microstructure.

If the anneal is to optimize for subsequent cold work, then you are still wasting money, becausethere are other ways to control cracking.

Furnace scale under rust preventive still equals rust.

milo Dont anneal 1215!

As already said, I don't see the need to anneal this steel after machining. Usual supply forms are cold drawn or as rolled.

The steel mentioned 11SMn30 is a free cutting steel with a low carbon content (11 means 0,11% "normal" or "average" content) and cannot be hardened just by heat treatment. Some of this free cutting steels can be hardened by carburizing or carbonitriding.

Any heat treatment of carbon steel will produce a rusty surface unless performed in a controlled atmosphere oxygen free (inert atmosphere) because of reactivity of iron and oxygen, which according to Arrhenius, increase the rate of reaction with increasing temperature. The only way to avoid rust is to avoid oxygen or to rectify/grind the surface after heat treatment (rather eliminating rusted surface)

You says After machined, the part goes for Annealing at suppler end(Tier 2). You mean that one end of "armature" must have a heat treatment? Why? It's really an annealing or a case hardening?

Kind regards