MECHANICAL PROPERTIES AND FRACTURE MECHANISMS OF COMMERCIALLY PURE MULTILAYER IRON PRODUCED BY STRIP JOINT ROLLING

Abstract

Multilayer materials (1.2–0.25 mm thick) are produced by sintering in a box at 850°С and cold rolling of ten-layer packages of commercially pure iron. It is shown that the tensile strength of the materials studied is proportional to the total true strain value by rolling and reaches 1400 MPa at relative elongation 1%. Fatigue limit increases up to 670 MPa. With increasing strain degree by rolling, the structural elements inside layers reduce in size, when high interlayer strength between macro layers. The best correlation of fatigue limit of materials with micro yield strength is observed, when 0.01% of residual strain.