av免费不卡在线观看网址,黄色视频大全ww,h在线观看网站,亚洲视频在线免费观看,男人天堂视频在线播放,日本女同羞羞视频,jk美女隐私视频网站

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.