消除某发动机壳体旋压裂纹的工艺改进

Process improvement on eliminating spinning cracks for a certain engine housing

薄壁、长形发动机壳体是弹箭类的关键零件,使用材料为D6AE高强度合金钢,对旋前毛坯进行球化退火处理,在强力旋压成形过程中筒体出现批量周向裂纹,裂纹呈鱼鳞状,由内腔沿壁厚向外表面延展而且裂纹位置集中。为解决该问题,基于强力旋压成形机理、成形工艺、热处理工艺等理论,对裂纹形貌、产生位置及旋压受力状态进行分析,获得了裂纹产生的根本原因,进而优选出在不增加成本的前提下通过改进旋压工艺得到的最佳解决方案:通过改善裂纹产生阶段的受力状态,使该阶段受力变小。该解决方案彻底消除了裂纹源,避免了重大经济损失,为大批量生产发动机壳体提供了良好的技术基础。

The thin-walled and long-shaped engine housing is a key component of projectiles and arrows, and the material used is D6 AE high-strength alloy steel. Before spinning, the blank is subjected to spheroidizing annealing treatment, and during the power spinning process, mass circumferential cracks appear on the cylinder body, which are fish-scale-like and extending from the inner cavity to the outer surface along the wall thickness direction, and the crack positions are concentrated. In order to solve the above problem, based on the theories of power spinning mechanism, forming process and heat treatment process, etc., the morphology, generating location and spinning stress state of cracks were analyzed to obtain the root cause of the cracks, and the best solution scheme obtained by improving the spinning process without increasing the cost was chosen, which improved the stress state in the crack generation stage to reduce the stress. Thus, the crack source was completely eliminated to avoid major economic losses in this solution scheme, which provided a good technical foundation for mass production of engine housing.