重油加氢脱硫装置和氨合成塔是在高温高压的严苛条件下操作的反应容器。从高温强度和防止氢损伤考虑,一般都选用铬钼系钢板作为制造材料,但这类材料具有回火脆性的问题,而回火脆性是指低合金钢在375—575℃温度范围内缓冷或在这一温度范围内保温时,由于杂质元素P、As、Sn、Sb等在前奥氏体晶界产生 Heavy oil hydrodesulfurization units and ammonia synthesis reactors operate under severe conditions of high temperature and pressure. From the high temperature strength and to prevent hydrogen damage, generally use chromium molybdenum steel plate as a manufacturing material, but such materials have the problem of temper embrittlement, and temper brittleness refers to low alloy steel in the 375-575 ℃ temperature range of slow cooling Or in the temperature range of insulation, due to the impurity elements P, As, Sn, Sb and other pre-austenite grain boundaries