Common defects and causes of steel pipes

Common defects and causes of steel pipes

Steel pipes are hollow and elongated steel bars, mainly used in industrial conveying pipelines and mechanical structural components such as petroleum, chemical, medical, food, light industry, mechanical instruments, etc. But in real life use, steel pipes also have common defects. Next, we will introduce the common defects and causes of steel pipes.

1、 Internal surface defects

Feature: Sawtooth shaped defects in the inner surface of the steel pipe, either straight or spiral or semi spiral.

Cause of occurrence:

1) Tube blank: central looseness and segregation; Severe residual shrinkage; Non metallic inclusions exceeding the standard.

2) Uneven heating of the billet, high or low temperature, and prolonged heating time.

3) Perforated area: Severe wear on the top; Improper adjustment of perforating machine parameters; Aging of perforating rollers, etc.

2、 Internal scarring

Features: The inner surface of the steel pipe shows scars, which generally do not take root and are easy to peel off.

Cause of occurrence:

1) Graphite lubricant contains impurities.

2) The iron ear at the rear end of the pipe is pressed into the inner wall of the steel pipe, etc.

3、 Warped skin

Features: The inner surface of the steel pipe presents a straight or intermittent nail shaped raised small skin. It often appears at the head of the capillary and is prone to peeling.

Cause of occurrence:

1) Improper parameter adjustment of the punching machine.

2) Stick steel at the top.

3) Accumulation of iron oxide scales inside the abandoned pipeline.

4、 Inner tympanum

Features: The inner surface of the steel pipe exhibits regular protrusions and there is no damage to the outer surface.

Cause: Excessive grinding of the continuous rolling roller.

5、 External scar

Features: The outer surface of the steel pipe shows scars.

Cause of occurrence:

1) The rolling mill is stuck to steel, aged, severely worn or damaged.

2) The conveyor roller conveyor is stuck with foreign objects or severely worn.

In short, there are many reasons for defects in steel pipes, but we should conduct timely inspections during use, identify and solve problems.

Shandong Kungang Metal Technology Co., Ltd. has year-round reserves of various steel pipe specifications to meet customer needs. Its products are distributed throughout the country, with reliable quality, professional customization, and long service life.