4Cr5Mo2V扁钢中AS14类退火组织成因分析  

Cause analysis of AS14 annealed microstructure in 4Cr5Mo2V flat steel

作　　者：陈建礼[1] 楚宝帅 张晓琨[1] Chen Jianli;Chu Baoshuai;Zhang Xiaokun(Technical Center,Shanxi Taigang Stainless Steel Co.,Ltd.,Taiyuan Shanxi 030003,China;Shanxi Key Laboratory of Metal Forming Theory and Technology,School of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan Shanxi 030024,China)

机构地区：[1]山西太钢不锈钢股份有限公司技术中心,山西太原030003 [2]太原科技大学材料科学与工程学院金属材料成形理论与技术山西省重点实验室,山西太原030024

出　　处：《金属热处理》2023年第5期66-69,共4页Heat Treatment of Metals

摘　　要：采用不同温度奥氏体化+贝氏体转变温度范围等温+球化退火工艺,模拟了4Cr5Mo2V扁钢中AS14类退火组织形成过程。利用Leica光学显微镜观察显微组织,采用438VP/KEVEX扫描电镜/能谱仪对试样微区化学成分进行分析,并对不同组织状态扁钢的冲击性能进行了测试。结果表明,终锻温度偏高,锻后在贝氏体转变温度范围停留或缓慢冷却导致钢中形成粗大的竹叶状贝氏体组织;退火时碳化物沿粗大贝氏体组织界面形核长大,而竹叶之间析出碳化物较少,从而形成了AS14类退火组织;AS14类退火组织具有较强的组织遗传性,能够显著降低扁钢的横向冲击性能;较低的终锻温度和冷却过程避免在贝氏体转变温度区间停留或缓慢冷却,可以防止4Cr5Mo2V扁钢形成AS14类退火组织。Austenitizing at different temperatures+isothermal treatment at bainite transformation temperature+spheroidizing annealing were used to simulate the formation process of AS14 annealed microstructure in the 4Cr5Mo2V flat steel.Leica optical microscope was used to observe the microstructure,438VP/KEVEX scanning electron microscope/energy dispersive spectrometer were used to analyze the chemical composition in the micro-area of the specimen,and the impact properties of flat steel with different microstructure were tested.The results show that,high final forging temperature leads to the formation of coarse bamboo leaf-like bainite in the steel due to staying within the bainite transformation temperature range or slow cooling after forging.During annealing,carbides nucleate and grow along the interface of coarse bainite,while fewer carbides precipitate between bamboo leaves,forming an AS14 annealed microstructure.The AS14 annealed microstructure has strong structural heritability,which can significantly reduce the transverse impact property of the flat steel.Lower final forging temperature and avoiding staying in the bainite transformation temperature range or slow cooling during cooling process can prevent the formation of AS14 annealed microstructure in the 4Cr5Mo2V flat steel.

关 键 词：4Cr5Mo2V扁钢 贝氏体 退火组织 组织遗传性 终锻温度 

分 类 号：TG142.1[一般工业技术—材料科学与工程]