Commonly Quality Problems of Mild Steel Pipe

In recent years, China's pipeline construction ushered in a new development of the peak. At the same time, the world market for steel pipe demand increases rapidly, so a large number of Chinese steel pipe exports. Behind the production and application of this prosperity, there have been some quality issues, some of the problems is indeed worrying. Quality of domestic mild steel pipe  Size deviation Size deviation in the straightness of the steel pipe, roundness and wall thickness uneven aspects. In most cases, little straightness tolerance of steel pipe used in the manufacture of standard steel pipe straightness requirements, if you exceed the specified value, will constitute a return of reason, therefore, the factory should be attention.  The roundness of the ultra-poor will affect the use of steel pipe, mainly on the wrong side of the group of welded joints. Will not only welded joints by the circular degree of tolerance resulting from the wrong side of bearing capacity of reduced also produce stress concentration. On-site group, some roundness of the steel pipe can be rectified, and some thick-walled steel pipe is not easily corrected. The outside diameter deviation and roundness of steel pipe used in a considerable difference.  The wall thickness of the uneven and generally easy to be ignored, and not clearly defined in many steel pipe standards. If the wall thickness and severe uneven, not only will cause the wrong side of the group on the joint, but also the secondary deformation processing (such as welded steel pipe manufacturing pipe fittings) adversely affect. Construction site feedback information on, serious non-uniform wall thickness steel pipe  Welding is very difficult. Therefore, many users started to pay attention and limit the wall thickness of the non-uniform bias. Structural steel pipe of uneven thickness deviation level of control actually reflects the level of manufacturing of the steel mills. Chemical composition .