CAJ | 학술논문

利用宏观分析、光谱成分分析、金相分析对内壁出现裂纹的06Cr18Ni11Ti不锈钢荒管进行了全面的分析。分析结果表明：扩管过程的开裂属于普遍开裂，材料的化学成分符合标准要求，裂纹两侧有少量TiN夹杂物，裂纹尾端呈沿晶趋势，奥氏体晶界有少许碳化物存在。因此推断退火效果不好导致晶界弱化，加之TiN夹杂物的应力集中，扩管张力的作用超过了材料的断裂强度时就发生了开裂。
이용굉관분석、광보성분분석、금상분석대내벽출현렬문적06Cr18Ni11Ti불수강황관진행료전면적분석。분석결과표명：확관과정적개렬속우보편개렬，재료적화학성분부합표준요구，렬문량측유소량TiN협잡물，렬문미단정연정추세，오씨체정계유소허탄화물존재。인차추단퇴화효과불호도치정계약화，가지TiN협잡물적응력집중，확관장력적작용초과료재료적단렬강도시취발생료개렬。
06Cr18Ni11Ti stainless steel pierced billet with inner cracks has been analyzed completely by means of macro analysis, spectrum composition analysis and metallurgical analysis.The result showed that cracks from pipe ex-panding process belonged to general crack, chemical composition of material conformed to standard requirement, TiN inclusion existed on both sides of crack, crack end tended to along grain change, and a few carbides existed in austen-ite grain boundary.Therefore it concluded that unsound annealing effect resulted in grain boundary weakening, stress concentration of TiN inclusion and pipe expanding tension action above material fracture strength have been taken place, all of the issues resulted in pipe expanding crack.