車輛使用的活塞环(如图1)要求是比較高的。它要求全面接触,弹力3～5公斤/平方公厘,在张开度为13公厘时不得有永久变形。我們采用的磷錫青銅的化学成分是:錫19.5～21.5％,磷0.2～0.4％,銅余量。我們知道,錫青銅的最大缺点是在鑄造过程中产生严重的成分偏析。它的鑄态組織是α+ε或α+δ。而这些组织对使用和机械加工都是极其不利的。 Piston rings used in vehicles (Figure 1) require a higher level. It requires full contact, elastic 3 ~ 5 kg / mm2, at the opening of 13 mm shall not have permanent deformation. The chemical composition of the phosphorus-tin bronze we use is: 19.5-21.5% tin, 0.2-0.4% phosphorus and the balance of copper. We know that the biggest disadvantage of tin bronze is the serious segregation of components during casting. Its as-cast structure is α + ε or α + δ. These organizations are extremely detrimental to both use and machining.