航天用高强度弹簧镀锌工艺替代方案研究

Study on substitute for zinc plating on aerospace high-strength spring

[目的]高强度弹簧是常用于为导弹空气舵、弹翼展开锁定提供驱动力的零件,通常采用高强度钢制造,以镀锌作为其表面防护手段,但该工艺过程存在氢脆导致弹簧脆性断裂的风险。[方法]分别对高强钢进行镀锌、镀锌镍合金、达克罗涂覆和离子镀铝,对比了不同镀(涂)层的厚度、结合力和耐蚀性,以寻找镀锌替代方案。[结果]达克罗涂覆、离子镀铝和镀锌镍合金都属于无氢脆或低氢脆表面处理工艺,但更推荐采用镀锌镍合金代替高强钢镀锌工艺。[结论]选择合适的表面处理工艺能够在一定程度上避免高强钢弹簧氢脆断裂问题。

[Introduction]High-strength springs are commonly used as the components to provide driving force for deployment and locking of missile air rudders and wings.These springs are usually made of high-strength steel and treated by zinc plating to offer a surface protection,but there is a risk of brittle fracture caused by hydrogen embrittlement during the zinc plating process.[Method]The high-strength steel was treated by zinc plating,zinc–nickel plating,Dacromet coating,and aluminum ion plating,respectively.The thickness,adhesion,and corrosion resistance of the four kinds of coatings were compared to find out a suitable alternative to zinc plating.[Result]The high-strength steels treated by Dacromet coating,aluminum ion plating,or zinc–nickel alloy plating has little or no hydrogen embrittlement,but zinc–nickel alloy plating is more recommended for replacing the zinc plating.[Conclusion]The brittle fracture of high-strength spring caused by hydrogen embrittlement can be solved by selecting a surface treatment technology properly.