av永久免费观看,日韩在线精品视频,在线观看国产视频,国产精品久久片,国产毛片av网站,国产又粗又硬又黄又刺激,国产黄色片视频

　a few days ago, based on the test plan made by the technology center, the steel-making plant succesfully produce U187 steel.　 

　　U187 steel is a high-end steel grade developed by the bridge rope project team of the company. Featuring high carbon, high silicon and micro alloy, this kind of steel has greater mechanical strength. The the strength of zinc-plate wire rope, which use U187 steel as material, can reach 1860Mpa, insured the bridge load bearing.

　　The technicians of technology center and steel-making plant involved in the whole production process. After sample analysis, the products were consisdered suitable for the next rolling process.