大型HT300主轴箱的铸造工艺

鉴于大型HT300主轴箱技术要求不允许出现裂纹、缩孔、渣孔等铸造缺陷,精心设计了铸造工艺方案和浇注系统,合理布置了冒 口、冷铁和加强筋；在1台7t冲天炉和2台5t中频电炉同时熔炼的条件下,采用含Ba的75SiFe长效孕育剂进行孕育处理,浇注温度1 340～1 360℃,浇注时间183 s.经测试,单铸试棒抗拉强度为320 MPa,落砂、清理及粗加工后未发现任何缺陷.

Casting Process of A Heavy Headstock Casting

The specification of large-scale headstock of grade HT300 was introduced. The defects such as cracks, shrinkages and slag eyes etc were not allowed. By elaborately designing the pouring position,moulding precedure and gating system, equitably distributing the risers, chills and reinforcing ribs, 1 set of 7-ton cupola together with 2 sets of 5-ton intermediate- frequency electric furnaces was used for melting,the inoculant of 75SiFe containing Ba was used for inoculating. Pouring tempreture was controlled in a range of 1 340 to 1 360 ℃. Pouring time was 183 seconds. By testing, the tensile strength of separate cast test bar was 320 MPa. No defect was found after shake-out, cleaning and rough machining.