How about the performance of 16Mn welded steel pipe

　　ASTM A106 Straight Seam Welded Steel Pipe is total alloy content is less than 3%. According to the strength, it is divided into four grades, namely 300, 350, 400 and 450 MPa. Mainly Q235, Q345, Q390, Q420 and Q460. "Q" is the head of the Chinese Pinyin capital letter of the yielding "Qu", followed by the number of the minimum yield point (σ s) value of the brand, followed by the symbol of a, B, C, D, etc. according to the content of impurity elements (s, P) in the steel from high to low and with the change of carbon and manganese elements. Among them, Grade A and B steels are usually called 16Mn.

　　16Mn welded steel pipe belongs to carbon manganese steel, with carbon content of about 0.16% and yield point of 343mpa (strength grade of 343mpa). 16Mn welded steel pipe has less alloy content and good weldability, so preheating is not necessary before welding. However, the hardening tendency of 16Mn steel is slightly larger than that of low carbon steel, so preheating measures should be taken to prevent cold cracks when welding at low temperature (such as outdoor operation in winter) or on structures with large rigidity and thickness.