Magnetic investigation of strain induced martensite evolution

In this work the magnetic properties of AISI 304L austenitic stainless steel was subjected by using the magnetic induction with different working frequencies. For this purpose a sheet rolled from 10 to 80% reduction at 0ᵒC was used. Then, by using Eddy current instrument at frequencies from 50 to 10000 Hz, magnetic behavior was studied. The results were made of two parts: (1) linear part where the reduction was lower than 10%, more non-magnetic transformation (Ɣ→ɛ) occurs in this region, (2) Exponential Rise to Max curve where the sudden increase in formation of ά-martensite (Ɣ→ά) and disappearing of ɛ-martensite occurs, lead to a sharp increase in permeability. Also an obvious relation between parameters of the function that fitted with it and structural changes was found

کلیدواژه ها:

Strain Induced Martensite ، Austenitic Stainless Steel ، magnetic induction ، NDE