Identification of Seamless Steel Pipe
A seamless steel pipe, a kind of long steel, has hollow section without seam. It is made from perforated tubular billets which are made of ingot steel or solid steel pipe and undergoes the process of hot rolling, cold rolling or cold drawn. Due to its hollow section, steel pipes are widely used for conveying fluids such as oil, natural gas, coal gas, water and some solid materials. Nowadays, there are so many seamless steel pipes in the market. Here are some tips for identifying and purchasing seamless steel pipes.
1. Inferior seamless steel pipes are easy to be scratched because manufacturers use poor production facilities, which will easily cause burrs and make the steel surface damaged. Serious scratches will even weaken the strength of steel pipes.
2. Inferior seamless steel pipes have no metallic luster, presenting in reddish or rusty colors.
3. The transverse bar of shoddy seamless steel pipe is thin and low and always can not be fully filled. In order to optimize the minus tolerance, the manufacturers adopted a little larger reduction in first several passes of finished products, making the iron mold a little smaller and the pass not completely filled.
4. A low-quality seamless steel pipe
has oval section because the producers adopted a little larger reduction in first two passes of finished products for saving materials. Not only the strength of the pipe,is weakened largely, but also its size can not meet the standard of seamless steel pipe.
5. Good-quality seamless stainless steel pipes feature in homogeneous materials, high tonnages cold shears, smooth crop ends, while poor-quality stainless steel pipes have rough crop ends without metallic luster.
6. The unqualified seamless steel pipe is comprised of many impurities with lower steel density, and severe dimension deviation problem. Given this, if there is no vernier calipers to use, we can weigh the pipe to make sure whether they are qualified or not.