国产精品久久久久久久久久免费动|久久久久免费精品国产|日日夜精品视频|黄色av地址,婷婷激情久久,亚洲美女高潮久久久,超碰在线三级

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 .