摘要
为确保低碳钢液压缸焊接工艺的可靠性,对其环焊缝的显微组织和硬度变化规律进行了研究。试样采用线切割进行截取,避免焊缝的二次热影响效应。截取后的试样通过热压镶嵌操作完成焊缝采样,通过不同颗粒度的水砂纸分别对镶嵌试样进行粗磨和细磨。抛光剂选用Cr2O3,腐蚀溶液选用4%硝酸酒精溶液。在金相显微镜400倍放大条件下观测不同焊缝区域的显微组织,分析组织形貌以及形成原因。设定不同方向的显微硬度测试路径,得出硬度变化规律,预测焊缝力学性能;受焊缝热源影响,热影响区组织有分成了过热区和正火区部分,该部分组织低于奥氏体相变温度,保留了少量的奥氏体晶核;焊缝区奥氏体晶核的数量逐渐增多,在熔池凝固的阶段中完成了相变过程。
In order to ensure the reliability of welding process of low carbon steel hydraulic cylinder,the variation law of microstructure and hardness of circumferential weld was studied.The sample was cut by wire cutting to avoid the secondary heat effect of the weld.The intercepted samples were sampled by hot pressing inlay operation,and the inlaid samples were roughly and finely ground by water sandpaper with different particle sizes.The polishing agent was Cr2O3,and the corrosion solution was 4%nitric acid alcohol solution.Under the condition of 400 times magnification of metallographic microscope,the microstructure of different weld areas was observed,and the microstructure morphology and formation causes were analyzed.The microhardness test paths in different directions were set,the hardness change law was get,and the mechanical properties of the weld was predicted.Under the influence of weld heat source,the structure of heat affected zone was divided into superheated zone and normalized zone,which was lower than the austenite transformation temperature and retained a small amount of austenite nucleus.The number of austenite nuclei in weld zone increased gradually,and the phase transformation process was completed in the solidification stage of molten pool.
作者
段修菊
Duan Xiuju(Zaozhuang Science and Technology Career Academy,Zaozhuang,Shandong 277599,China)
出处
《机电工程技术》
2022年第12期92-94,共3页
Mechanical & Electrical Engineering Technology
关键词
金相
显微组织
硬度
试样制备
力学性能
metallography
microstructure
hardness
sample preparation
mechanical property
