Embrittlement of advanced nickel(3)-aluminum alloys by hydrogen and grain boundary incipient melting

In this dissertation embrittlement of Ni;Hydrogen embrittlement has been studied in continuous cast sheet of IC-50. When tensile-tested at the initial strain rate of 5.8 ;Thermal treatments were performed on continuous cast IC-50 sheet, investment cast IC-50 rod and IC-218 ingot. The incipient melting temperatures of GB in the alloys were determined by microstructural analysis after quick heating and quenching from different temperatures. The GB in IC-50 sheet, IC-50 rod and IC-218 ingot started to melt at 1250;Autogenous gas tungsten arc welding was performed on continuous cast IC-50 sheet, IC-50 cast bar and IC-396M ingot. They were susceptible to cracking in the heat-affected zone (HAZ). The low melting temperature of GB caused by segregation of Zr was the reason for high sensitivity to liquation cracking in HAZ. (Abstract shortened with permission of author.).