Effect of Severe Deformation on Secondary Hardening and Fracture Behavior in W Containing Co-Ni Alloy Steels

摘要

Two kinds of Co-Ni steels, containing the only W(W steel), and the W and Cr(WCr steel), were severely rolled at 800 or 900□, followed by direct quenching(DQ). DQ specimens were then isothermally aged at 450 and 475□. Secondary hardening occurred as the fine M_2C carbides precipitated as the cementite dissolved. The severe deformation at the relatively low temperature austenite region enhanced both hardness and impact toughness. The Cr addition promoted aging through compositional and/or structural modifications of the M_2C carbide.