Have you found the problems with steel pipes? Details are as following:
1. The internal and external quality of steel pipes
The appearance quality problems of steel pipes include: external folds, cracks, splits, holes, punctures, external threads, corrections, bumps, pitted surfaces, rolling, folding.
2. Quality problems of geometric dimensions
Outer diameter tolerance, wall thickness tolerance, length tolerance, ellipticity tolerance, bending(straightness tolerance), inner hexagon, steel tube unilateral
3. Unqualified quality problems of physical and chemical properties
According to the contract or standard steel pipe, the chemical composition (mixed steel or alternative steel), tensile strength, yield strength, impact performance, hardness, elongation, flattening performance, flaring, bending performance etc are unqualified, and the main reasons why above problems occur are that one is the production of mixed materials, the other is the contract to replace steel and the third is that the production process is not strictly controlled.
4. Quality problems of tubing and casing threads
Velcro, trip, tight pitch of thread, thread grease, eccentricity of threaded thread, unfastened coupling
5. Quality problems of users in the process of processing and use
There are middle cracks, pores, processing fractures, inclusions
6. The quality of packaging labeling
Rust, unclear markings, loose bundles, incorrect markings
