THE DIFFERENCE OF PRIMARY PROPERTIES OF HOMEMADE & FOREIGN LSAW STEEL PIPES

The primary properties of the LSAW pipes formed from JCOE technology which have the same grade,wall-thickness,dimension and from which the steel band are manufacturing by different factories are compared and analyzed. The primary properties that have been tested and analyzed include chemical composition,tensile test,charpy impact test etc. It is proved that the steel pipe manufactured by the steel band of a steel manufacturing factory have more higher tensile strength and more higher value of charpy impact test in low temperature than that of foreign mill,moreover among of those the yielding strength and the value of charpy impact test of pipe-body have more difference. The average yielding strength of the steel bodies manufactured by the steel band of a steel manufacturing factory is 33MPa higher,and the average value of charpy impact test is 107J than that of foreign mill. It is also analyzing the causes which result in the differences above.