16Mn钢焊接研究——毕业设计论文.doc.doc

16Mn钢焊接研究 摘 要 16Mn钢是具有高强度、高韧性和耐腐蚀等优良特性的低合金高强钢，是我国低合金高强钢中用量最多、产量最大的钢种用于制造桥梁、船舶、车辆、锅炉、高压容器、输油输气管道、大型钢结构等。热处理后的焊接接头晶粒明显比未热处理过的要细小，组织结构更加均匀。硬度升高。因此，热处理可以改善焊接接头的组织，并提高其性能。 Welding Research of 16Mn Steel Abstract 16Mn steel is a low alloy high strength steel which has high strength, high toughness and corrosion resistance and other excellent characteristics. It has the largest amount and the largest steel production among the low alloy high strength steel in China. It is widely used in manufacture of bridges, ships, vehicles, boilers, pressure vessels, pipelines, large steel structure. In view of the importance of 16Mn steel in ours industry and national economy, also 16Mn steel welding is an essential technology, so the welding of steel 16Mn study is significant for practical application. In this issue 16Mn steel was welded by SMAW, the changes welded joint were analyzed in the organization and performance; welded joints were obtained by normalizing processing, and analyzed the changes of the organization and performance between before and after heat treatment. The results show that the weld zone is the columnar crystal; fusion zone is coarse crystal; hot area is the widmanstatten structure; completely crystalline region is the ferrite and pearlite; one part of incomplete crystalline region is the small Ferrite and Pearlite, another is the coarse Ferrite. The coarse crystal of the 16Mn steel welded joint fusion zone and the widmanstatten structure of the 16Mn steel welded joint hot area as the result of Cold cracking and HAZ. So it was processed by normalizing after welding, welded joints after heat treatment were significantly higher than the grain is not heat treated to small and more uniform structure. Hardness was increased accordingly. Therefore, heat treatment of welded joints can improve the organization and improve its performance. Research of 16Mn steels SMAW, microstructure and properties of welded joints, heat treatment after welding can be used as a refere