狠狠操2019|爱爱视频网址|欧美在线视频导航|www.xxxxx,欧美日本激情,tvb银狐电视剧粤语高清在线观看,好好生活免费观看完整版高清在线

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.