CAJ | 학술논문

　　针对大截面辊轴发生延迟崩裂的现象，采用逻辑反推法，进行宏、微观断口形貌、显微组织结构、力学特性、化学成分分布及内应力分析，并进行去氢退火试验验证。结果表明：由于冶炼过程中未能有效除氢，局部氢含量偏高及辊轴调质热处理产生的残余应力，使辊轴内残存氢发生聚集膨胀导致延迟崩裂；辊轴断裂模式为氢脆解理断裂。提出从冶金除氢、锻后去氢处理和控制热处理加热速度3方面加以预防。
　　침대대절면곤축발생연지붕렬적현상，채용라집반추법，진행굉、미관단구형모、현미조직결구、역학특성、화학성분분포급내응력분석，병진행거경퇴화시험험증。결과표명：유우야련과정중미능유효제경，국부경함량편고급곤축조질열처리산생적잔여응력，사곤축내잔존경발생취집팽창도치연지붕렬；곤축단렬모식위경취해리단렬。제출종야금제경、단후거경처리화공제열처리가열속도3방면가이예방。
According to the delayed crack of a large cross?section roller shaft,and by using logical reverse?deduction method,the macro and micro fracture morphology,the microstructure,mechanical properties,distribution of chemical composition and internal stress were analyzed,and dehydrogenation annealing verification test was carried out. The results show that the fracture mode is hydrogen embrittlement and cleavage fracture. Dehydrogenation is not effective during smelting process,which results in local high hydrogen content,and residual stress during the process of quenching and tempering treatment. Thereby,the remnant of the hydrogen gathering and expanding in the roller shaft causes delayed crack. Finally,it is proposed that fracture can be prevented in the following 3 aspects:hydrogen reducing in smelting process,dehydrogenation treatment after forging and control of heating rate in heat treatment.