日韩亚洲一区中文字幕在线,黄色视频免费观看网站,9191精品国产免费久久,欧美日韩三四级视频在线观看,亚洲国产成人久久综合碰,国产午夜av毛片久久,真人抽搐一进一出gif免费木瓜视频

Xingtai Steel high quality spring steel wire rod 55SiCrA is mainly used in the production of automobile suspension spring, it has higher resistance to play performance, using strength reduction, the fatigue test must reach 500000 times without fracture.This steelhas a very high requirements in the process of smelting and rolling on chemical composition, inclusion quantity and shape distribution, gas content, surface quality, the decarburization layer, microstructure, mechanical properties, high dimensional accuracy and other requirements.Customers reflect the various performance indicators such as mechanical propertiesof steel rolling materials, non-metallic inclusion, surface quality and the depth of decarburization layer, can meet the quality requirements.