B对X100/X120高强度管线钢连续冷却相变组织的影响  

Effect of B on Microstructure of X100/X120 High Strength Pipeline Steel During Continuous Cooling Transformation

作　　者：王炜[1] 赵征志[2] 王莹[1] 朱涛[1] 

机构地区：[1]马鞍山钢铁股份有限公司,安徽马鞍山243000 [2]北京科技大学冶金工程研究院,北京100083

出　　处：《钢铁》2012年第7期64-67,共4页Iron and Steel

基　　金：北京市科委重大项目(D09030303780902)

摘　　要：利用热模拟技术(DIL805A热膨胀仪)和显微分析方法,对不同成分体系X100/X120高强度管线钢在连续冷却转变下的显微组织的变化规律进行了研究。研究结果表明,对于无B钢,随冷速增加,组织中依次出现多边形铁素体(PF)、粒状贝氏体(GB)、贝氏体铁素体(BF)和马氏体(M)。B元素的添加使得管线钢相变开始温度降低到500℃左右,抑制了多边形铁素体的形成,促进了贝氏体的形成。为了获得高级别管线钢X100的复相组织,无B钢的冷却速度应控制在20～30℃/s,而含B钢的冷速只需控制在5～15℃/s,简化了冷却工艺。Microstructures in continuously cooled X100/X120 high strength pipeline steels were investigated by means of heat simulation technique on a thermal dilatometer（DIL805A） and optical microscope.The results show that the microstructures of samples in B free steel are changed from polygonal ferrite,granular bainite,bainitic ferrite to lath martensite with the cooling rate increases.B addition in the pipeline steels can decrease the start temperature of austenite transformation to about 500 ℃,inhibit the formation of the polygonal ferrite and promote the formation of bainite.To achieve the microstructure constitutes of X100 pipeline steel,the cooling rate for B free steel is 20-30 ℃/s,while the cooling rate for B bearing steel is 5-15 ℃/s,simplify the cooling process.

关 键 词：连续冷却转变 显微组织 冷速 

分 类 号：TG142.1[一般工业技术—材料科学与工程]