欧洲精品乱码久久久久蜜桃,72式性无遮挡在线观看视频,夜夜操夜夜干,一区二区三区在线免费观看,色91av,欧美激情片一区二区,91cn国产在线

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.