THE MECHANISMS AND DETECTION OF EMBRITTLEMENT IN Cr‐Mo PRESSURE VESSEL STEELS
THE MECHANISMS AND DETECTION OF EMBRITTLEMENT IN Cr‐Mo PRESSURE VESSEL STEELS
复制标题
Cr-Mo压力容器钢脆化机理及检测
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
P. Kelly
中科院分区：
文献类型：
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作者：
C. Moss;P. Kelly
摘要：21/4CrlMo钢和11/4Cr1/2Mo钢已广泛应用于水力处理装置，如水力脱硫和水力裂化反应器。这些反应堆压力容器钢具有回火脆化的潜力，导致韧性下降和脆性断裂的临界缺陷尺寸减小。这些钢也容易发生氢脆，特别是在老化钢中，裂纹可能在母材中扩展到临界缺陷尺寸。因此，在最初建造时具有足够韧性的容器可能在使用过程中发生脆化，这种变化可能需要在启动和关闭期间限制压力。对文献的调查表明，成分是回火脆（TE）和氢脆（HE）的控制参数，特别是残余杂质元素（如P）和元素（如Mo）的存在，它们抵消了杂质偏析的影响。许多资料可用于描述Cr - Mo钢的脆化现象。本文回顾了TE和HE的机制，并描述了一种微观结构表征路线，该路线随后允许对潜在脆化容器的结构完整性进行检查，以评估剩余寿命和延长植物寿命。版权
Abstract— 21/4CrlMo steel and 11/4Cr1/2Mo steel have been widely been used for hydro‐processing units such as hydro‐desulphurising and hydro‐cracking reactors. These reactor pressure vessel steels have a potential for temper embrittlement that leads to toughness degradation and a reduction of the critical flaw size for brittle fracture. These steels are also susceptible to hydrogen embrittlement, especially in aged steels where cracks may propagate in the base metal up to the critical flaw size. A vessel with adequate toughness when originally constructed may therefore embrittle during service and such changes may require pressure restrictions during start‐up and shut‐down. A survey of the literature shows composition to be the controlling parameter for both temper embrittlement (TE) and hydrogen embrittlement (HE), in‐particular the presence of residual impurity elements such as P and the presence of elements such as Mo which nullify the effect of impurity segregation. Much information is available to describe embrittlement phenomena for Cr‐Mo steels. This paper reviews the mechanisms of TE and HE and describes a microstructural characterisation route which subsequently allows the structural integrity of potentially embrittled vessels to be examined for the purposes of remaining life assessment and plant life extension. Copyright