Hydrogen Service Failures of Welds With Insufficient Alloy Content^★ Available to Purchase

Low chromium-molybdenum alloys were used successfully in refineries to prevent hydrogen damage. Nevertheless welds failed under certain conditions after long exposure to hydrogen. A case history is discussed involving a weld in the channel of a reactor charge-effluent exchanger which saw service at 950 F and hydrogen partial pressure of 375 psi. It was found that the welds failing in service had inadequate chromium and molybdenum contents. 3.7.3, 8.4.3, 6.2.4