摘要
采用扫描电镜和光学显微镜对断面收缩率为44%、38%、32%的3个SWRH82B盘条试样的拉伸断口、显微组织进行观察。3个试样拉伸断口均呈现韧窝断口形貌,断裂模式为韧性断裂;显微组织分别为索氏体、网状渗碳体＋索氏体、马氏体＋索氏体,网状渗碳体断裂形成的裂纹微孔呈现一定棱角形貌,马氏体断裂形成的裂纹微孔横向扩展。依据韧性断裂的微孔聚集理论分析推导了3种盘条试样的微孔形成、扩展过程,阐述了网状渗碳体、马氏体导致盘条试样断面缩率降低的原因。结果表明,中心偏析导致盘条芯部出现网状渗碳体和条带马氏体组织是断面收缩率较低的根本原因。
The tensile fracture morphology and microstructure of three SWRH82 B wire rod samples with reduction of area 44%,34%,32%respectively were observed.The test results show that tensile fracture of the three samples has dimple morphology of ductile fracture.The microstructure of the three samples is sorbite,sorbite ＋ network cementite and sorbite ＋ martensite respectively.The crack microvoid as a result of the fracture of the network cementite presents a certain angle shape.The crack microvoid as a result of the fracture of martensite broadwise extends.On the basis of the mechanism of microvoid coalescence fracture,the processes of microvoid nucleation and growth are deduced and the reasons of lower wire rod area reduction are expounded.The results of analysis indicate that the reason for lower area reduction is the network cementite and martensite structure in the core of wire rod caused by center segregation.
作者
秦树超
黄翠环
赵昊乾
王昆鹏
Qin Shuchao;Huang Cuihuan;Zhao Haoqian;Wang Kunpeng(Xingtai Iron and Steel Co.,Ltd.,Xingtai Hebei 054027,China;Hebei Province Wire Engineering Technology Research Center,Xingtai Hebei 054027,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2018年第10期242-246,共5页
Heat Treatment of Metals
关键词
断面收缩率
网状渗碳体
马氏体
微孔聚集
断裂
percentage of area reduction
network cementite
martensite
mierovoid coalescence
fracture
