前言飞龙牌自行车曲柄是种长轴类制件,材质LD10。要求有足够的抗拉强度和抗弯强度,现行的锻造制坯工艺是完全可以满足要求的。但由于工序繁多,生产周期长,原材料利用率低,能耗大,造成产品成本高。为此,1981年开始,由黑龙江省国防工办主持,向阳林业机械厂和哈尔滨工业大学合作,就飞龙牌自行车 Foreword Dragon bike bicycle crank is a kind of long shaft parts, material LD10. Require sufficient tensile strength and bending strength, the current forging billet process is fully meet the requirements. However, due to many processes, long production cycle, low utilization of raw materials, high energy consumption, resulting in high product costs. To this end, started in 1981, presided over by the Defense Department of Heilongjiang Province, Xiangyang Forestry Machinery Factory and Harbin Institute of Technology, the dragon brand bicycle