Microstructure, mechanical properties and corrosion behavior of 65Mn tape-steel via electromagnetic induction heating

The heat treatment of electromagnetic induction heating (EMIH) was employed on 65Mn tape-steel. Microstructure evolution of 65Mn tape-steel was systematically characterized by scanning electron microscope and electron backscatter diffraction. Then the mechanical properties of microhardness, tensile, and corrosion resistance tests were examined. After EMIH treatment, the network-like of cementite was broken. The ferrite precipitates are melted into a large number of small particles, which were attached to the matrix. The microhardness of 65Mn tape-steel treated with EMIH is lower than that of the as-received. The average microhardness values decrease gradually with the increase of duration times during the EMIH treatment. After the treatment, the ultimate tensile strength (UTS) and tensile yield strength (TYS) reduce to about 700 MPa and 600 MPa, respectively. Meanwhile, the values of the UTS and TYS can't be affected by a further increase of alternating current (AC) values. The elongation (EL) increases with duration time increasing from 1 s to 3 s. However, the EL declines to 1.3% and 0.5% after EMIH is treated with oil/water cooling, respectively. At an electric current value of 210 A, the sample demonstrates better corrosion resistance than the other samples.