Rectangular tube, also known as square tube or rectangular tube, is a kind of square steel with a hollow section. At present, there are two main forming processes for square tubes, which are the round-to-square and the direct-to-square.

Eddy current testing and magnetic flux leakage testing are both commonly used non-destructive testing methods for seamless steel pipes. The two mainly detect the surface and near-surface defects of steel pipes. Both have their own focus and limitations. Choose according to the situation.

Nitriding treatment refers to the chemical heat treatment process in which nitrogen atoms infiltrate the surface of the steel pipe in a certain medium at a certain temperature. The common ones include liquid nitriding, gas nitriding, and ion nitriding. The purpose is to improve the surface hardness and wear resistance of the steel pipe. Improve fatigue strength, corrosion resistance, etc.

The magnetism of the seamless tube is due to the magnetism of martensite or ferrite, and a small amount of martensite or ferrite will be formed during component segregation or improper heat treatment during movement. In this way, there will be weak magnetism in the seamless tube. At this time, it is necessary to demagnetize the seamless steel pipe.

There are three main connection methods when connecting galvanized pipes, namely wire type, welding type and rolling groove type. 1. If the thread type method is used, the thread buckle cannot be in complete contact with the pipe hoop of the steel pipe, otherwise it is likely to become loose. Before connecting, it is necessary to measure whether the wall thickness of the steel pipe can reach the standard thickness of the thread. If the thread of the steel pipe does not match the thread of the pipe hoop and cannot be connected, the pipe hoop should be replaced or the equipment should be adjusted to re-thread the thread.

In order to improve the anti-corrosion conditions of the medium, the following two methods can be used.①Remove harmful components in the medium. ②Add corrosion inhibitor. Corrosion inhibitor is a substance that can slow down the corrosion rate. Adding corrosion inhibitor is a common and effective anti-corrosion measure. Different corrosion inhibitors are only effective in certain environments.