The Effects of Deaerated Water on the Toughness of Nickel-Based Alloys

The fracture toughness of nickel based alloys can be degraded when exposed to low temperature

deaerated water. This paper uses elastic-plastic fracture mechanics testing to explore some

fundamental environmental and metallurgical factors that influence this form of environmentally

assisted cracking. Elastic-plastic fracture toughness tests were performed on 0.6T compact

tension samples of EN82H weld metal as a function of temperature, hydrogen content in the

water, and hydrogen content in the weld metal. These results are used in conjunction with

literature data and fundamental understanding to outline the environmental and material

conditions that promote susceptibility to this form of hydrogen embrittlement.