65Mn材质钢锹断裂分析  

Fracture Analysis on 65Mn Material Spade

作　　者：罗昌森[1,2] 罗宏[1,2] 王莹[1,2] 

机构地区：[1]四川理工学院材料与化学工程学院,四川自贡643000 [2]材料腐蚀与防护四川省重点实验室,四川自贡643000

出　　处：《热加工工艺》2013年第2期199-201,206,共4页Hot Working Technology

基　　金：材料腐蚀与防护四川省重点实验室开放基金项目(2012CL08)

摘　　要：采用自回火方法热处理的钢锹产品在施工现场出现了批量断裂的现象,应用扫描电子显微镜观察断口,金相显微镜分析显微组织,洛氏硬度计测量硬度值。结果表明:混凝土施工现场断裂钢锹的金相组织是马氏体与少量的回火马氏体,产品强度硬度高、塑性韧性低、易脆断,原因是应用自回火热处理工艺时,淬火的冷却时间长,产品温度下降多,余热未能使产品达到自回火温度;钢锹断口为沿晶断裂,能谱分析发现晶间存在夹杂物,夹杂物的聚集进一步削弱了材料晶间结合力,促进材料脆性化。河沙施工现场断裂钢锹的金相组织为铁素体与马氏体,该组织不适宜做工具产品,其断口微观形貌由准解理、韧窝、孔洞构成。The spade products treated with the self-tempering method appeared batch quantity fracture phenomenon at the construction site. The fracture was observed using SEM, the microstructure was analyzed using OM, and the hardness was measured using Rockwell hardness machine. The results show that： at the concrete construction site, the fracture microstructure of the spade consists of martensite with a small amount of tempered martensite, the product has high strength and hardness, low toughness and plasticity, vulnerability. The above reason is the application of the self-tempering treatment process with that so long cooling time of quenching and so much drop of the product temperature that make heat can not reach self-tempering temperature. Spade fracatre is intergranular fracture, EDS analysis find intergranular inclusion whose aggregation makes further weaken the material intergranular bonding strength, and promotes brittleness. At the sand construction site, the fracture rnicrostructure of the spade consists of ferrite and martensite, the microstructure is unfit for tool products, its fracture micro-appearance consists of quasi-cleavage, dimple and holes.

关 键 词：钢锹 断裂 显微组织 65Mn 

分 类 号：TG157[金属学及工艺—热处理]