Mechanism of improved ductility of 1500 MPa-class ultra-high strength cold-rolled steel sheet produced by rolling and partitioning method

Hosoya, Yoshihiro*; Matsumura, Yuta*; Tomota, Yo*; Onuki, Yusuke*; Harjo, S.   

In this paper, the microstructure formation during the R&P process and the deformation mechanism that would bring about the excellent strength-ductility balance are discussed based on the results obtained from the in situ neutron diffraction measurement. The results have revealed that the typical Luders-like stress-strain curve of R&P steel is caused by competitive plastic flow between austenite and martensite, and an effective transformation induced plasticity phenomenon.