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研究低碳微合金X80和X100管线钢分别在未变形和变形条件下的连续冷却转变(CCT)行为。用G leeb le-2000热模拟试验机,结合OM、SEM和TEM等方法测定未变形和变形奥氏体的连续冷却转变曲线,并对不同冷速和变形条件下的组织进行观察分析。结果表明,冷速较低时,连续冷却转变组织主要为多边形铁素体和珠光体,随着冷速提高依次出现块状铁素体,粒状铁素体,针状铁素体,贝氏体铁素体等组织。热变形能强烈促进针状铁素体的形成,使针状铁素体的相变温度提高50~100℃,并使CCT曲线向左上角移动,同时使晶粒细化及取向更加无序。
The continuous cooling transformation (CCT) behavior of low-carbon micro-alloy X80 and X100 pipeline steel under undeformed and deformed conditions was studied. The continuous cooling transformation curves of undeformed and deformed austenite were determined by G leeb le-2000 thermal simulator combined with OM, SEM and TEM. The microstructures under different cooling rates and deformations were observed and analyzed. The results show that when cooling rate is low, the structure of continuous cooling transformation is mainly polygonal ferrite and pearlite. With the increase of cooling rate, massive ferrite, granular ferrite, acicular ferrite, bainite Ferrite and other organizations. Thermal deformation can strongly promote the formation of acicular ferrite, the acicular ferrite transformation temperature increased by 50 ~ 100 ℃, and the CCT curve to the upper left corner, while the grain refinement and orientation more disorder.