塑性变形及消应力热处理对10CrNi5MoV钢性能与组织的影响  

Effect of Plastic Deformation and Stress Relief Heat Treatment on Microstructure and Properties of 10CrNi5MoV Steel Plate

作　　者：王任甫[1] 邓晚平[1] 牛继承[1] WANG Renfu;DENG Wanping;NIU Jicheng(Luoyang Ship Material Research Institute,Luoyang 471023,China)

机构地区：[1]中国船舶重工集团公司第七二五研究所

出　　处：《材料开发与应用》2019年第5期16-21,26,共7页Development and Application of Materials

摘　　要：分析了塑性变形量分别为2.4%、3.2%、4.8%、6.6%和9.1%的10CrNi5MoV钢在消应力热处理前后力学性能和微观组织的变化。结果表明,10CrNi5MoV钢具有包申格效应,热处理后该效应消除、屈服强度恢复正常,但低温韧性较热处理前有不同程度的降低,且下降幅度随着试样塑性变形增大而增加;当塑性变形量为9.1%时,出现了明显脆化,断口呈韧窝+准解理+沿晶断裂的混合断裂形貌;包申格效应的产生、消除与塑性变形引起的位错密度变化有关;热处理后马氏体板条间条状碳化物的析出以及P、Ni元素和部分碳化物在晶界处的偏聚,致使晶内和晶界部分脆化是该钢在较大塑性变形下韧性下降的主要原因。The changes of mechanical properties and microstructures of 10 CrNi5 MoV steels, with plastic deformation of 2.4%, 3.2%, 4.8%, 6.6% and 9.1% before and after stress relief heat treatment were explored. The results show that 10 CrNi5 MoV steel has Bauschinger effect. After stress relief heat treatment, the effect is eliminated and the yield strength returns to normal, but the low temperature toughnesses decrease in varying degrees compared with that before stress relief heat treatment, the decreasing range of which increases with the increasing of plastic deformation. When the plastic deformation is 9.1%, obvious embrittlement occurs and the fracture surface presents dimples, quasi-cleavage fracture and intergranular fracture mixed morphologies. The generation and elimination of the Bauschinger effect are related to the change of dislocation density caused by plastic deformation. The embrittlement of part of the grains and the grain bougdaries caused by the precipitation of strip carbides between martensite laths and the segregations of P and Ni elements and some carbides at grain boundaries is the main reason for the decreasing of toughness of the steel with relatively large plastic deformation.

关 键 词：10CrNi5MoV 消应力热处理 塑性变形 脆化 条状碳化物 偏聚 

分 类 号：TB302[一般工业技术—材料科学与工程]