Recover Heat Treatment for Cobalt Base Superalloy HA188 after Creep Fatigue Damage

Abstract

HA188 cobalt-base superalloy is generally used under the high temperature environment. The mechanical properties of the alloy decrease under creep fatigue condition in high temperature as gas turbine components. In this study, the recovery of deteriorated properties was tried using heat treatment, and the condition for recovery was found. Concretely the elongation and the reduction of area at room temperature of Alloy 188 was decreased after creep fatigue applied the tensile stress 80 MPa at 1000°C, and the degenerate properties were recovered after heat treatment at 1100°C/1 h/fan cooled.