【摘要】 2Cr12NiMoWV钢制高温紧固螺栓在高温下长期服役，会出现硬度上升、韧性降低的脆化现象。分析表明：硬度升高是由于碳化物在基体内部弥散析出，产生弥散硬化；而晶界网状碳化物的析出是造成冲击韧性降低的主要原因。经过适当的恢复热处理，可使脆化螺栓的硬度降低、冲击韧性升高，重新满足使用要求。最佳的恢复热处理工艺为：1055～1070℃加热油冷淬火，710℃×6h回火。更多还原

【Abstract】 After working at high temperature for a long time, the embrittlement of fastening bolts made of 2Cr12NiMoWV steel occurs with the increasing of their hardness and the decreasing of their impact toughness. The analytical results show that the dispersed carbides precipitating on the martensitic matrix cause dispersion hardening and make hardness of bolts increase. The network-like carbides precipitating along grain boundaries are the main reason to make impact toughness drop. By restoring heat treatment, hardness can be decrease, impact toughness can be increase and embrittlement of bolts can be eliminated. The optimum process of restoring heat treatment is 1055～1070℃ heating, oil cooling and 710℃×6h tempering.更多还原