1990 年 76 巻 6 号 p. 894-901
Effects of alloying elements and thermomechanical treatment on mechanical and magnetic properties of Cr-Ni austenitic stainless steel have been investigated.
N and Si increase hardness after cold rolling as well as strain age hardening. Si decreases γ stability with respect to α' transformation, while other alloying elements increase it. Nonmagnetism can be maintained by controlling Nieq, an index of γ stability. High strength-nonmagnetic stainless steel can be obtained by utilizing strain age hardening and Nieq.
Si changes deformation mode from dislocation multiplications to formation of stacking faults. Si increases X-ray halfwidth at a given cold rolled condition, while decreasing it after aging treatment. It is considered that a large strain age hardening by Si is attributed to increase of internal strain and precipitation hardening. The decrease of γ stability by the addition of Si may be due to the accerelation of formation of α' phase by virtue of ε phase.