用于制造高性能同步器齿毂的Astaloy CrA烧结-硬化材料

HIGH PERFORMANCE SINTER HARDENING MATERIALS FOR SYNCHRONIZING HUBS

同步器齿毂正在向形状较复杂与较高使用性能发展,同时在生产成本上也受到很大压力。当今许多高性能同步器齿毂都是由各种,诸如Distaloy AE与Distaloy HP之类扩散粘结粉末生产的。新的要求是希望材料与制造工艺具有好的性价比。这意味着不使用价格不稳定,而且高的纯镍与钼,最好改用以铬为基的,不用或添加少量纯镍的预合金化粉末。Astaloy CrA与Astaloy LH都是适用于烧结硬化的预合金化粉末。通过添加数量不同的铜或镍及含碳量可制得所需要的不同强度。利用CCT(连续冷却转变)-图,可利用冷却速率来选择最佳组成。

The development of synchronizing hubs goes towards more complicated shapes and higher performance, at the same time as there is a strong pressure on costs. Today many high performance synchronizing hubs are produced using different diffusion bonded materials like Distaloy AE and Distaloy HP. With the new demands it is a desire to move to materials and processes with better cost/performance ratio. This means to move away from high and unstable costs for pure nickel and molybdenum to pre-al[oyed materials preferable based on chromium with none or smaller additions of plain nickel. Astaloy CrA and Astaloy LH are pre-alloyed powders suitable for sinter hardening. By selecting different additions of copper or nickel as well as the carbon content the properties can be tailored for different strength requirements. The usage of CCT-diagrams can assist in the selection of the optimal composition depending on which cooling rate that can be applied.