CAJ | 학술논문

室温应变强化技术可大幅提高奥氏体不锈钢的屈服强度，显著减薄容器壁厚，已广泛应用于奥氏体不锈钢深冷容器制造。采用金相显微镜、X 射线衍射仪（XRD）、透射电子显微镜（TEM）和摆锤式冲击试验机研究应变强化对 S30408奥氏体不锈钢低温冲击性能的影响。结果表明：材料在应变强化过程中发生应变诱发相变，相变产物为α′和ε马氏体，深冷低温对应变强化材料的相组成和含量影响不大。随着应变量的增加和温度的降低，材料冲击吸收能量 KV2降低，其中裂纹扩展能 EP基本不变，裂纹形成能 Ei显示与总冲击吸收能量相似的变化趋势。当温度低于77 K，冲击吸收能量下降趋于平缓，呈现出“平台”现象，且应变强化对材料低温冲击性能的影响要大于温度对其的影响。即使经过15％应变量，材料仍表现出较好的低温冲击韧性。
실온응변강화기술가대폭제고오씨체불수강적굴복강도，현저감박용기벽후，이엄범응용우오씨체불수강심랭용기제조。채용금상현미경、X 사선연사의（XRD）、투사전자현미경（TEM）화파추식충격시험궤연구응변강화대 S30408오씨체불수강저온충격성능적영향。결과표명：재료재응변강화과정중발생응변유발상변，상변산물위α′화ε마씨체，심랭저온대응변강화재료적상조성화함량영향불대。수착응변량적증가화온도적강저，재료충격흡수능량 KV2강저，기중렬문확전능 EP기본불변，렬문형성능 Ei현시여총충격흡수능량상사적변화추세。당온도저우77 K，충격흡수능량하강추우평완，정현출“평태”현상，차응변강화대재료저온충격성능적영향요대우온도대기적영향。즉사경과15％응변량，재료잉표현출교호적저온충격인성。
The yield strength of austenitic stainless steel could be increased by strain-strengthening at room temperature.Stain-stretching technique can reduce the wall thickness of vessel,and has been widely used in austenitic stainless steel cryogenic vessel.The effect of strain-strengthening on impact property of S30408 austenitic stainless steel was investigated by using optical microscopy,X-ray diffraction,transmission electron microscope and pendulum impact testing machine.The results show that α′-and ε-martensite phase were strain-induced during the strain-strengthening.The effect of microstructure and volume percent of phase on materials after stain-stretching was small.The impact absorbed energy(KV2 )decreased with increasing deformation and temperature drop.The crack propagation energy EP is almost unchanged,but its crack initiation energy Ei showed a similar trend with the total KV2 .When the temperature was lower than 77 K,the decreasing of impact absorbed energy tended to be smooth,and showed a “platform”phe-nomenon.The effect of strain strengthening on cryogenic impact property of materials is greater than the effect of cryogenic temperature.Even after strained 15%,the material was still showing a greater low tem-perature impact toughness.