Crystallographic insights into the role of nickel on hardenability of wear-resistant steels

Abstract Two wear-resistant steel plates with different Ni content were studied to reveal the significant role of Ni on hardenability from the perspective of crystallography. From the surface to the quarter, and then to the center of the plates, the 0.44Ni steel exhibited higher hardness compared with the 0.02Ni steel, indicating that the 0.44Ni steel was of higher hardenability. The microstructure at the center changed from granular bainite to lath bainite with increased Ni content, together with an enhanced density of block boundaries. Ni improves the hardenability by weakening the variant selection through inducing larger transformation driving force and more self-accommodation of transformation strain to obtain a high density of block boundaries.