The quality identification techniques of large diameter thick-walled seamless steel pipe are as follows:

1 Inferior large diameter thick-walled seamless pipe is easy to fold. The fold is formed on the surface of large diameter thick-walled seamless tube polyline, this defect is often longitudinally throughout the entire product. Generating folded shoddy manufacturers to pursue high efficiency, the amount of reduction is too large, resulting in the ears, generated under a rolling folding, the folded products after bending will crack, the strength of the large diameter thick-walled seamless The large decline.

2 Shoddy large diameter thick-walled seamless appearance often pockmarked face. The pockmarked face serious groove wear caused by the large diameter thick-walled seamless tube defects of uneven surface irregularities. Shoddy large diameter thick-walled seamless pipe manufacturers to the pursuit of profit, it is often the most excessive groove rolling.

3. Shoddy large diameter thick-walled seamless surface prone to scarring.

4 Inferior surface of the sheet is easy to produce cracks, because it dough adobe adobe many pores, the adobe due to thermal stress in the cooling process, resulting in cracks, after after rolling there crack.

5 Shoddy large diameter thick-walled seamless easily scratched because of shoddy material manufacturers poorly equipped, easy to produce glitch, scratching the large diameter thick-walled seamless surface. The depth scratching reduce the strength of large diameter thick-walled seamless.

6 Shoddy large diameter thick-walled seamless metallic luster, pale red color like pig iron, because there are two two it blank is adobe. 2, the shoddy rolling temperature is not the standard, the temperature of the steel by visual observation, so that can not be carried out according to the provisions of austenitic area rolling, large diameter thick-walled seamless performance standards naturally not.