97超碰人人澡人人,久久久一区二区,亚洲天堂色图片,7777精品伊人久久久大香使用方法,国产午夜一区,日韩av中文字幕一区二区,国产黄色大片儿

　　The material QML45Mn2 of Xingtai Iron and Steel Corp.,Ltd mainly used to produce the rivets for train. For this steel ,it has stable composition, low content of residual elements and strict size control. A terminal customers used the product for a long time, very few quality question, and has switched all procurement of raw materials to our products.