不同冷却速率对508-Ⅲ钢显微组织的影响  

The Effect of Different Cooling Rates on Microstructure of 508-ⅢSteel

作　　者：刘东海 刘涵赜 LIU Donghai;LIU Hanze(Casting and forging steel business department of CFHI,Qiqihaer 161042,Heilongjiang,China;Tianjin Heavy Equipment Engineering Research Co.,Ltd.,Tianjin 300457,China)

机构地区：[1]中国第一重型机械股份公司铸锻钢事业部,黑龙江齐齐哈尔161042 [2]天津重型装备工程研究有限公司,天津300457

出　　处：《热处理技术与装备》2025年第2期57-61,共5页Heat Treatment Technology and Equipment

摘　　要：反应堆压力容器所使用的508-Ⅲ钢材质,在实际生产过程中厚锻件浅表层区域能够形成马氏体组织,然而其心部区域则倾向于形成上贝氏体与粒状贝氏体,此现象可能导致低温冲击性能和落锤试验结果出现波动。为探究不同冷却速率对微观组织与低温冲击韧性之间关系的影响,对试样进行了不同冷却速率处理。研究结果显示,在较低的冷却速率下,材料中形成的粒状贝氏体含有少量层片状珠光体组织及大量岛状混合贝氏体组织。随着冷却速率的提高,马奥岛体积增大,组织逐渐由粒状贝氏体转变为上贝氏体和马氏体。这一发现对后续回火组织关于冲击韧性影响的机理分析具有重要的指导意义。The 508-Ⅲsteel material used in the reactor pressure vessel can form martensite in the shallow surface layer of thick forgings during actual production,while the core area tends to form upper bainite and granular bainite.This phenomenon may cause fluctuations in low-temperature impact performance and drop weigh test results.To explore the influence of different cooling rates on the relationship between microstructure and low temperature impact toughness,this study treated the samples at different cooling rates.The research results show that at a lower cooling rate,the granular bainite formed in the material contains a small amount of lamellar pearlite structure and a large amount of island-shaped mixed bainite structure.As the cooling rate increases,the volume of the M/A islands increases,and the microstructure gradually changes from granular bainite to upper bainite and martensite.This finding has important guiding significance for the subsequent analysis of the mechanism of the effect of tempering microstructure on impact toughness.

关 键 词：508-Ⅲ钢 冲击韧性 微观组织 冷却速率 

分 类 号：TG142.1[一般工业技术—材料科学与工程]