Liquid metal embrittlement (LME) susceptibility of the 8-9% Cr martensiticsteels F82H-mod., OPTIFER IVb and their simulated welded structures in liquid Pb-17Li

This paper describes the results of uniaxial tensile tests on two low activ ation steels F82H-mod, and OPTIFER IVb. The tests were performed under vacu um and in liquid Pb-17Li at temperatures of 250 degreesC and 400 degreesC a t a constant displacement rate of 0.1 mm min(-1), which corresponded to an initial strain rate of 1.1 x 10(-4) s(-1). Neither F82H-mod. nor OPTIFER IV b exhibited a liquid metal embrittlement (LME) susceptibility in the temper ed fully martensitic state. However, tests of the heat affected zone (HAZ) specimens indicated an LME susceptibility for both steels tested at 250 deg reesC in Pb-17Li, while increasing the test temperature to 400 degreesC led to the recovery in ductility. The effect of post-weld heat-treatment (PWHT ) of the HAZ specimens of 750 degreesC/1 h for F82H-mod. and 730 degreesC/3 h for OPTIFER IVb was sufficient to regain the majority of their original mechanical properties. (C) 2000 Elsevier Science B.V. All rights reserved.