Temper Embrittlement of 2.25Cr-1Mo Steel Base Metal and Welded Material

The theory of equilibrium grain boundary segregation was applied to analyze grain boundary segregation of P element for base metal and welded material of test block.The agreement between theoretical and experimental results have shown that with the increasing of servicetime,the temper embrittlement degree of hydrogenation reactor base metal and welded material gradually increases,and among which increasing rate of embrittlement degree for welded material is obviously higher than that of base metal.For hydrogenation reactor in service for 10×104 hours,the welded material is still in accelerated temper embrittlement stage,while the temper embrittlement for base metal is close to saturation.The theoretical proof of equilibrium grain boundary segregation can explain the phenomenon of temper embrittlement for hydrogenation reactor material.