How to prevent scratches and white rust on seamless carbon steel pipes

How to prevent scratches and white rust on seamless carbon steel pipes

Seamless carbon steel pipes are widely used in pipelines for transporting fluids, such as natural gas, oil, water pipelines, etc. Seamless carbon steel pipes can be divided into hot-rolled carbonless seamless steel pipes and cold-drawn seamless carbon steel pipes. Hot-rolled seamless steel pipes are also called general-purpose steel pipes and can be divided into low- and medium-pressure boiler steel pipes. In addition, there are alloy steel pipes, stainless steel pipes, petroleum cracking pipes, geological steel pipes and other steel pipes. Cold-rolled seamless steel pipes are not only divided into ordinary steel pipes, low and medium pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, but also other steel pipes like hot-rolled steel pipes.

Seamless steel pipes have the advantages of high pressure resistance, good toughness, long pipe sections, and few joints, and are widely used in the manufacture of structural parts and mechanical parts. For example, automobile transmission shafts, bicycle frames, oil drill pipes, steel scaffolding for construction, etc., all use steel pipes to make ring-shaped parts. In addition, the rolling bearing rings and jack rings we often see are made of seamless steel pipes.

The characteristics of scratches and abrasions on seamless steel pipes are vertical and linear scratches of different lengths on the inner and outer surfaces of seamless steel pipes, which are mostly groove-shaped, but may also be raised stripes.

The main cause of scratches and abrasions on seamless steel pipes is. There are internal scratches on the pipe that cannot be eliminated during drawing, and there is iron oxide scale remaining on the seamless steel pipe. The mold sticks to the steel, the strength and hardness of the mold are insufficient or uneven, the mold is broken and worn, the sharp shuttle angle of the transition part of the hammer head damages the mold, etc.

In order to prevent scratches and abrasions, the quality of each preparation process before deep drawing should be improved, and the strength, hardness and smoothness of the mold should be improved. When electroplated seamless steel pipes need to be stored and transported in an airtight manner, appropriate precautions should be taken to prevent white rust, maintain a low humidity environment around key parts, and ensure adequate ventilation between stacking parts to reduce white rust. rust. Details are as follows.
1. Surface treatment can reduce the occurrence of white rust.
2. Paint should be stored in dry and well-ventilated conditions.
3. If the paint can only be stored in the open air, the paint should be separated from the floor by narrow partitions so that air can flow freely to all surfaces of the paint.
4. Do not place coated parts where they may be affected by rain, stomach, condensation and snow.

5. The galvanized steel bottom should be checked on the surface of the ship or placed on the bottom of the ship to avoid contact with bilge water during surges.