Fake and inferior steel pipes are prone to folding. Folds are various fold lines formed on the surface of steel pipes. This defect often runs throughout the longitudinal direction of the product. The reason for folding is that shoddy manufacturers pursue high efficiency and the reduction is too large, resulting in ears. Folding will occur during the next rolling process. The folded product will crack after bending, and the strength of the steel pipe will be greatly reduced.
The appearance of fake and inferior steel pipes is often pitted. The pitted surface is an irregular uneven defect on the surface of the steel pipe caused by severe wear of the rolling groove. Due to the pursuit of profits by fake and inferior steel pipe manufacturers, groove rolling often exceeds the standard.
The surface of fake and inferior steel pipes is prone to scarring. There are two reasons:
1. The material of fake and inferior steel pipes is uneven and contains many impurities.
2. The guide equipment of fake and inferior material manufacturers is simple and easy to stick to steel. These impurities can easily cause scarring after biting the rollers.
The surface of fake and inferior materials is prone to cracks because its raw material is adobe, which has many pores. The adobe is subject to thermal stress during the cooling process, causing cracks, and cracks appear after rolling.
Fake and inferior steel pipes have no metallic luster and are light red or similar in color to pig iron. There are two reasons:
1. Its blank is adobe.
2. The rolling temperature of fake and inferior steel pipes is not standard. Their steel temperature is measured by visual inspection. In this way, rolling cannot be carried out according to the specified austenite area, and the performance of the steel pipe will naturally not meet the standards.
The transverse ribs of fake and inferior steel pipes are thin and low, and they often appear to be underfilled. The reason is that to achieve a large negative tolerance, the manufacturer’s reduction in the first few passes of the finished product is too large, the iron shape is too small, and the hole pattern is not filled.
Post time: Apr-12-2024