X70管线钢强韧化机制的研究  

Mechanism of Strengthening and Toughening of X70 Steel for Pipeline

作　　者：牛继龙 郑建平 

机构地区：[1]南京钢铁股份有限公司板材事业部,江苏南京210035

出　　处：《热处理》2017年第6期31-35,共5页Heat Treatment

摘　　要：X70钢是一种用于制作管线的超低碳贝氏体钢,可通过控轧空冷工艺使之获得稳定的力学性能。采用透射电镜(TEM)研究了热轧后X70钢的显微组织,以揭示其强韧化机制。结果表明,热轧后X70钢试样中产生了大量尺寸细小、分布均匀的含铌和钛的碳化物和碳氮化物,且形成了大量的位错网络和位错缠结,产生亚晶强化。研究表明,X70钢的强韧化机制为析出强化和亚晶强化。X70 steel is a ultra-low-carbon beinitic steel from which pipeline is made, and its stable mechanical properties may be obtained by a controlled rolling and controlled cooling technology. Microstructure of the X70 steel after hot-rolling was surveyed by means of a transmission electron microscope （TEM） to discover the mechanism whereby it is strengthened and toughened. The results showed that a great number of carbides and carbo-nitrides containing niobium and titanium, as well as a large amount of dislocation network and dislocation tangle, formed in the X70 steel specimen after hot-rolling, producing a sub-grain strengthening effect. From the investigation it was seen that the X70 steel permitted to be strengthened and toughened by sub-grain or precipitation.

关 键 词：X70超低碳贝氏体钢 管线 控轧控冷工艺 显微组织 

分 类 号：TG335.5[金属学及工艺—金属压力加工]