国内精品久久久久久久日韩,成人国产视频在线观看,亚洲精品国产一区二区,少妇一级淫片免费放在线,视色av,国产精品美女久久久av,蜜桃av网站

Main Products
steel for machine structure Products>> Main Products>> steel for machine structure
Products Grade: 20Cr2MnMoA
Specifications: φ20~28mm
Applied Standard:  agreement
Characteristics: this product is used to produce continuous sucker rods.
Applications: Sucker rod
Use of Products: This grade has the feature of stable chemical composition, low harmful elements(O、N) and nonmetallic inclusions, minor decarburization, good surface quality,good plasticity and notched bar impact strength after heat treating.Now our product is used in Shengli Oil Field.