CAJ | 학술논문

某电厂锅炉末级过热器出口导汽管弯头硬度值偏低，为查清原因，对试样进行化学成分分析、常温拉伸试验、高温拉伸试验、硬度测试、金相组织分析。结果表明：该弯头成分符合要求，常温和高温力学特性不符合要求，金相组织不是回火托氏体组织；判定P91弯管热处理工艺控制不严，回火温度偏高，得到回火索氏体组织，导致硬度降低，力学特性变差。
모전엄과로말급과열기출구도기관만두경도치편저，위사청원인，대시양진행화학성분분석、상온랍신시험、고온랍신시험、경도측시、금상조직분석。결과표명：해만두성분부합요구，상온화고온역학특성불부합요구，금상조직불시회화탁씨체조직；판정P91만관열처리공예공제불엄，회화온도편고，득도회화색씨체조직，도치경도강저，역학특성변차。
In a certain power plant,exit pipe elbows of final stage of superheater are at lower hardness. In order to find out the reason,chemical composition analysis,mechanical properties test at room temperature and high temperature,hardness test, microstructure observation were carried out. The results show that the composition is eligible,the mechanical properties fall short of request,The microstructures are not tempered troostite. The reasons of lower hardness and worse mechanical properties of P91 elbow are that the heat treatment process isn’t controlled strictly,the tempering temperature is on the high side,which results in tempered sorbite.