铸造冷却速率对CB2钢微观组织和力学性能的影响  

Effect of Casting Cooling Rate on Microstructure and Mechanical Properties of CB2 Steel

作　　者：马煜林 刘越 江旭 刘春明 穆建华 李敏 崔野 杨程坤 MA Yu-lin;LIU Yue;JIANG Xu;LIU Chun-ming;MU Jian-hua;LI Min;CUI Ye;YANG Cheng-kun(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,Liaoning,China;Liaoning Fu-An Heavy Industry Co.,Ltd.,Anshan 114000,Liaoning,China)

机构地区：[1]东北大学材料科学与工程学院,辽宁沈阳110819 [2]辽宁福鞍重工股份有限公司,辽宁鞍山114000

出　　处：《铸造》2018年第11期1016-1020,共5页Foundry

基　　金：国家重点基础研究发展计划-973计划(2011CB610405);辽宁省科技重大专项(201404001)

摘　　要：采用SEM、TEM和拉伸试验机研究了铸造冷却速率对CB2钢的显微组织和力学性能的影响,分析不同冷却速率对CB2钢中夹杂物的含量、马氏体板条的宽度、析出相的形态和δ铁素体的含量的影响。研究发现:CB2-F和CB2-S钢的夹杂物比例分别为0.196 9%和0.0655 6%;两种钢的马氏体板条平均宽度分别为268.90 nm和301.46 nm;较大的冷却速率能够细化钢中的M_(23)C_6相,并能够减少室温下钢中δ铁素体的含量。较高的冷却速率可以提高CB2钢的强度。此外,在回火后的CB2-S钢的δ-铁素体中观察到长度约为100 nm,直径约为20 nm的M_3C相。δ-铁素体的存在降低了CB2-S钢的析出强化和位错密度。The effect of cooling rate on the microstructure and mechanical properties of CB2 steel was investigated using SEM, TEM and tensile tester. The effects of cooling rate on the content of inclusions, width of martensite laths, morphology of precipitated phases and content of δ-ferrite in CB2 steel were analyzed. It is found by the study that the contents of inclusions in CB2-F and CB2-S steels are 0.196 9% and 0.065 56%, respectively; the average widths of martensite laths in these two steels are 268.90 nm and 301.46 nm, respectively. By increasing the cooling rate, the M23C6 phase in the CB2 steel can be refined, the content of ferrite in the steel can be reduced, and the strength of the steel can be improved. Furthermore, the M3C phase with an approximate length of 100 nm and a diameter of 20 nm was observed in the δ-ferrite of CB2-S steel after tempering, and the presence of δ-ferrite reduces the precipitation strengthening and dislocation density of CB2-S steel.

关 键 词：CB2钢 微观组织 M23C6 Δ铁素体 力学性能 

分 类 号：TG27[金属学及工艺—铸造]