Effect of heat treatment on properties of austenite S30432 stainless steel elbow pipe for boiler application

A new austenite S30432 stainless steel elbow pipe was prepared, and the effect of heat treatment on properties of S30432 elbow pipe was investigated. The results show that austenite grains become coarse and ununiform through the solution strengthening at 1150°C, but they become fine and uniform at 1110°C or 1060°C, with the grain size coming up to level 8~9 at the largest deformed zone and kept unchanged at the undeformed one. While, after the solution strengthening at 1110°C or 1060°C, the deformed zone's tensile strength of the elbow pipe is higher and the plasticity changes little in comparison with that before solution strengthening. It is concluded that the optimum solution processing temperature for S30432 elbow pipe is from 1060°C to 1100°C, at which through the solution strengthening the mechanical properties and grain size all satisfy the specifications for super-super boiler pipe application.