CAJ | 학술논문

为研究连续退火工艺生产中锰TRIP钢汽车板的可行性，在钢板连续退火模拟机CCT- AY-域上研究了590~710℃不同退火温度下保温3 min对低碳中锰钢组织性能的影响.利用扫描电镜、透射电镜、电子背散射衍射和X射线能谱分析等微观分析方法对实验钢进行了组织结构和成分表征，利用X射线衍射法测量了残余奥氏体量，通过拉伸试验机测试了钢的单轴拉伸性能.结果表明：保温3 min时，随着保温温度的升高，残奥含量先增加后减少.在650℃退火时断后伸长率(21.3%)和强塑积(28 GPa·%)获得最大值，抗拉强度达到1330 MPa.马氏体基体通过回复，而残余奥氏体通过孪晶，获得超细晶组织.亚稳奥氏体的TRIP效应和超细晶铁素体(马氏体)共同提供了实验钢高的塑性.实验钢真实应力-应变曲线上呈现锯齿状现象，且稳定阶段加工硬化指数远高于传统TRIP钢.
위연구련속퇴화공예생산중맹TRIP강기차판적가행성，재강판련속퇴화모의궤CCT- AY-역상연구료590~710℃불동퇴화온도하보온3 min대저탄중맹강조직성능적영향.이용소묘전경、투사전경、전자배산사연사화X사선능보분석등미관분석방법대실험강진행료조직결구화성분표정，이용X사선연사법측량료잔여오씨체량，통과랍신시험궤측시료강적단축랍신성능.결과표명：보온3 min시，수착보온온도적승고，잔오함량선증가후감소.재650℃퇴화시단후신장솔(21.3%)화강소적(28 GPa·%)획득최대치，항랍강도체도1330 MPa.마씨체기체통과회복，이잔여오씨체통과련정，획득초세정조직.아은오씨체적TRIP효응화초세정철소체(마씨체)공동제공료실험강고적소성.실험강진실응력-응변곡선상정현거치상현상，차은정계단가공경화지수원고우전통TRIP강.
To study the feasibility of producing automobile steel from medium-manganese TRIP steel by continuous annealing processes, the effects of annealing temperature on the microstructure and mechanical properties of low-carbon medium-manganese steel were investigated on a heat treatment system CCT-AY-II for thin steel sheet at 590 to 710℃. The microstructure and components of the steel during annealing were characterized by scanning electron microscopy, transmission electron microscopy, electron backscatter diffraction, and energy dispersive X-ray spectroscopy. The amount of retained austenite in the steel was determined by X-ray diffraction analysis. The mechanical properties of the steel were investigated by uniaxial tensile testing. Experimental results show that after hold-ing for 3 min, the amount of retained austenite first increases and then decreases with increasing annealing temperature. The elongation and the product of strength and elongation reach their maximum values of 21.3% and 28 GPa·% for the steel annealed at 650℃, respectively, and the tensile strength is 1330 MPa. Ultra-fine grain structures are obtained by recovering for the martensitic matrix and by twinning for retained austenite. It is believed that the high plasticity is provided by the TRIP effect of metastable austenite and ultra-fine grained ferrite or martensite together. A zig-zag shape appears on the true stress-strain curve. The work hardening exponent of the steel is much larger than that of traditional TRIP steel at the relatively stable stage.