小孔径超高强度钢筒体零件的近净成形加工技术研究

针对超高强度钢强度高、每次允许的变形量小、形变强化严重等特点，通过变形程度的分配、变形工序的安排和变形方式的选择，对小孔径超高强度钢筒体零件进行了温挤压制坯、冷拉深成形的近净成形加工技术研究。该技术解决了传统小孔径超高强度钢筒体制造过程中存在的内孔尺寸精度低、表面质量差、内孔加工困难以及后续切削加工余量大等关键问题，降低了超高强度钢筒体的裂纹敏感性，提高了超高强度钢筒体的承载能力，可满足大批量工业生产要求。

Study on the Near-net Forming Technique of Shell Body with Small Blind Holl Made by Ultra-high-strength Steel

According to the material characteristics of the ultra-high-strength steel, the near-net forming technique will be obtained by the proper arrangement of deformation stage, suitable distribution of deformation degree and rational choice of blank, design of the cold ironing die sets and the warm extruding die sets. It used for the shell body with thin wall and deep blind hole made by the ultra -high-strength steel and could be manufactured in high volume production. The key technical problems including the dimensions and surface quality of deep blind hole, the machining technology of shell deep blind hole etc. were solved by this near-net forming process. At the same time, the resistance to deformation is improved and the crack sensitivity is reduced for the shell body made by the ultra-high -strength steel,achieve the goal of mass production.