As part of a design for a new electron energy analyzer design, we will be using 316L stainless steel for some of the optics parts. While 316L stainless steel is naturally non-magnetic due to its austenitic crystal structure, intense machining, such as cutting or drilling induces stress that converts some austenite into magnetic martensite, and the result is that the 316L will be very slightly magnetic. For our application we need to have all the optics parts be non-magnetic.
The solution is to anneal the 316L parts by heating to 1100C and then cooling rapidly back to room temperature. Annealing reverses this magnetic effect by allowing the distorted lattice to relax back into its original non-magnetic state.
In my search for a company that can provide an annealing service I came across MET-TEK Inc.
Their prices are very reasonable and besides annealing they offer a variety of services including –
- Controlled atmosphere hardening
- Vacuum hardening and tempering
- Carburizing & carbonitriding
- Solution annealing and age hardening
- Annealing, normalizing and stress relieving
- Aluminum solution treating, aging and annealing
- Gas nitriding
- Precision straightening
- Glass bead & Rotoblast cleaning
- Cryo treating down to -200F
- Metallurgical Lab Services
I mention MET-TEK as a resource as it is sometimes hard to find a company that can provide annealing services at a reasonable price.