【摘要】 基于夏比冲击试验,获得不同脆化态、脱脆态和充氢态2.25Cr-1Mo-0.25V钢母材及焊缝的韧脆转变温度,定量评价材料的回火脆和氢脆倾向。由不同脆化态的韧脆转变温度发现:2.25Cr-1Mo-0.25V钢母材抗回火脆性能明显优于焊缝。充氢前后韧脆转变温度结果表明:回火脆化后的母材及焊缝的韧脆转变温度下降显著,同时脆化出现趋于饱和现象。根据充氢前后材料微观断口,对回火脆与氢脆协同作用机制进行探讨,发现回火脆化后,氢吸附于基体内析出的碳化物以及氢与杂质元素在晶界处的偏聚是材料脆化的主要原因。更多还原

【Abstract】 The ductile-brittle transition temperature of base metal and weld metal of 2.25 Cr-1 Mo-0.25 V steel under different temper embrittlement, de-embrittlement and hydrogen charging states were obtained by the Charpy impact test. The tendency of temper embrittlement and hydrogen embrittlement were then evaluated. From the ductile-brittle transition temperatures under different temper embrittlement states, it was found that the temper embrittlement resistance of 2.25 Cr-1 Mo-0.25 V base metal was better than that of weld metal. The results of ductile-brittle transition temperature before and after hydrogen charging showed that for the base metal and weld metal which had been tempered and embrittled, the ductile-brittle transition temperature of the steel decreased significantly, and the embrittlement tended to be saturation. The mechanism of synergistic effect of temper embrittlement and hydrogen embrittlement on the steel was discussed according to the micro-morphology before and after hydrogen charging. It was found that the main reason of embrittlement was the hydrogen adsorbed on carbides precipitated in the matrix and the segregation of hydrogen and impurity elements at the grain boundary after tempering.更多还原