分级热处理对钻杆材料力学行为的影响  

Effect of marquenching and tempering heat treatment on mechanical behaviors of drill pipe steel

作　　者：韩礼红 姜新越 冯耀荣 蔡和平[3] 王青林 

机构地区：[1]中国石油集团石油管工程技术研究院,陕西西安710065 [2]渤海能克钻杆有限公司,河北青县062658 [3]西安交通大学材料科学与工程学院,陕西西安710049

出　　处：《材料热处理学报》2011年第4期97-103,共7页Transactions of Materials and Heat Treatment

基　　金：中国石油天然气集团公司应用基础研究项目(06A40102)

摘　　要：对S135钢级石油钻杆进行了分级淬火及回火热处理,获得下贝氏体/马氏体型复相组织。对其拉伸、冲击及疲劳性能进行了试验研究,并通过透射电镜原位拉伸试验对其微观断裂机制进行了观察与分析。结果表明:在保证强度的前提下,下贝氏体相的引入可以提高钻杆钢的韧性。室温夏比V型缺口冲击韧性高达178 J,远远超过当前的调质态钻杆,可满足高强度钻杆"先漏后破"断裂准则的需求。复相组织中的下贝氏体片交割原奥氏体晶粒,具有显著的细晶强化作用。下贝氏体相的引入有效提高了微裂纹萌生及扩展阻力,使材料的抗疲劳性能显著提高。Multi-phase microstructure including lower bainite and martensite of S135-graded drill pipe steel was achieved by marquenching and tempering processes.Tension,impact and fatigue properties of the steel were studied after different heat treatment processes.Fracture mechanism of the steel was studied by in-situ TEM tension test.The results show that the toughness of the steel can be greatly increased by introducing lower bainite phase,which does not decrease strength for S135-graded drill pipe steel simultaneously.The ambient impact toughness in Charpy V shape notch reaches 178 J,and exceeds that of as-received material,which can meet the requirement of drill pipe steel with high strength according to fracture principle of leak before break.In-situ TEM observations revealed that prior-austenite grain is fragmented by lower bainite sheets,and grain refining effect is obvious.Meanwhile,lower bainite sheets can effectively resist crack nucleation and propagation,and the fatigue property of the drill pipe steel is improved.

关 键 词：分级淬火及回火 下贝氏体/马氏体 钻杆 强韧性 断裂机制 

分 类 号：TG113.2[金属学及工艺—物理冶金]