成人免费a视频,李雅在线观看一区国产,五月婷婷狠狠,精品国产自在2o18,狼伊人,五月天丁香婷婷网,久久亚洲精品无码观看不卡

Casus Products>> Casus

  Q37MnB5 material is a kind of European standard steel developed by Xingtai Steel. It is base on common carbon structure steel, adding trace boron element and increasing manganese content to improve that hardenability of steel and reducing cold-heating deformation tension. A customer of Xingtai Steel uses the steel to produce automobile engine structure parts and 10.9 grade high strength bolts. The customer reflects that the product has stable chemical composition , good cold heading performance and low inclusion content , and can fully meet the requirements .