What factors can cause corrosion of cold drawn seamless pipes?

Posted by chase Liu on August 9th, 2023

Cold drawn seamless tubing is a kind of seamless pipe, that is, it is classified according to different production processes, which is different from hot-rolled (expanded) pipes. It is processed by multi-pass cold drawing in the process of expanding the diameter of the blank or raw material tube, usually on a 0.5~100T single-chain or double-chain cold drawing machine

Cold-rolled (dial) steel pipes are in addition to general steel pipes, low and medium pressure boiler steel pipes, high-pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, machined pipes, thick-walled pipes, small-diameter cold-drawn pipes with internal molds, and other steel pipes. It also includes carbon thin-walled steel pipes, alloy thin-walled steel pipes, stainless steel thin-walled steel pipes, and special-shaped steel pipes. The outer diameter of cold-drawn steel pipe can reach 6mm, schedule 40 pipe, and the outer diameter of thin-walled pipe can reach 5mm and the wall thickness is less than 0.25mm. The precision and surface quality are obviously better than hot-rolled (expanded) tubes, but due to process constraints, its caliber and length are limited to a certain extent.

The surface quality, appearance and dimensional accuracy of cold-drawn seamless pipes are better than hot-rolled seamless pipes, and the thickness of the products is as thin as 0.18mm, so they are favored by the majority of users. So what factors will lead to corrosion of cold drawn seamless pipe?

The corrosion problem of cold drawn seamless steel pipe is already a serious problem. For many manufacturers, the cost of corrosion is also constantly rising, and the direct economic loss caused by photocorrosion reaches hundreds of millions of yuan every year, which is a very huge expenditure. Therefore, the corrosion should be dealt with in time to recover economic losses. Why do cold drawn seamless steel pipes corrode? These factors may be directly related to corrosion. Specifically, let's take a look at the relevant introduction:

1. The first is the influence of external conditions. The main thing is to first look at the characteristics and temperature of the medium around the pipeline, and whether the medium around the pipeline is corrosive. Because the corrosiveness of the medium is closely related to the various microorganisms contained in the soil. And if it is a long-distance pipeline, the nature of the soil environment is more complicated. In addition, the temperature of the environment in which the pipeline is located will also affect the corrosion of cold drawn seamless steel pipes. If the temperature is higher, the corrosion rate will be accelerated, and if the temperature is low, the corrosion rate will be slowed down.

2. It is anti-corrosion failure. When the pipeline is erected, it is necessary to do a good job of anti-corrosion work or directly use anti-corrosion cold-drawn seamless steel pipes. The reason for the corrosion of the pipeline is that the anti-corrosion layer of the pipeline has been damaged. Once the anti-corrosion layer and the surface of the pipeline are separated, it will naturally cause anti-corrosion failure.

Note: The corrosion of steel pipes will seriously affect the quality of the project, so many manufacturers will choose to galvanize seamless or welded steel tubes.