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××机前起落架转轴接头,原材料为30CrMnSiNiA,零件净重8.5公斤,是一个重要受力件,结构复杂.如图1.原用万吨水压机压制的白由锻坯经机加而成,锻坯重200公斤,机加工时在1000小时以上.后改为万吨水压机上模锻,毛坯重55公斤,机加工时为215小时.工艺成本高,工时多,生产周期长,材料利用率低,又需要大型锻压设备,为解决这一生产关键,我厂从1966年开始改用熔模精密铸造法试制.设计要求铸件按《结构钢精密铸件技术标准》的Ⅰ类铸件验收,检查项目为每炉做化学成份、机械性能、逐个铸件作X光透视、磁力探伤,尺寸和表面质量检查,铸件材料为ZG27CrMnSiNi,机械性能要求σ_h=140±10公斤/毫米~2、δ_5>5%、α_k>1.7公斤·米/厘米~2、HB=3.3～2.85毫米(压痕直径).
× × front landing gear shaft connector, the raw material for the 30CrMnSiNiA, parts net weight of 8.5 kg, is an important force component, the structure is complex as shown in Figure 1. The original white tonnage hydraulic press by the white from the forging by machining, forging Billet weight 200 kg, machining time of more than 1,000 hours later changed to 10,000 tons of hydraulic press on forging, rough weighing 55 kg, machining time of 215 hours. High process costs, working hours, long production cycle, low material utilization , Also need large forging equipment, in order to solve the production of the key, I plant from 1966 to use investment casting precision casting trial design requirements of castings “structural steel precision castings technical standards” Class I castings acceptance inspection items Each furnace made of chemical composition, mechanical properties, cast one by one for X-ray, magnetic inspection, size and surface quality inspection, the casting material is ZG27CrMnSiNi, mechanical properties require σ_h = 140 ± 10 kg / mm2, δ_5> 5%, α_k > 1.7 kg · m / cm 2, HB = 3.3 ~ 2.85 mm (indentation diameter).