304 stainless steel square tube is not certain that stainless steel will rust under certain standards. Even high-quality sus316l304 stainless steel square tube is not listed. Therefore, according to this scruples, we also have a higher pursuit of perfection for the safety factor and added value of 304 stainless steel square tube raw materials in application. The way to complete this provision is to carry out reasonable stainless steel passivation on the raw materials of 304 stainless steel square pipe and produce passivation treatment protective film. For such problems, countries all over the world have promulgated various processing process specifications and established regulations and standards for passivation treatment of 304 stainless steel square tubes in chemical plants, crude oil, driving force, nuclear engineering, aerospace and other industries. Objective facts show that 304 stainless steel square tube can only be passivated by stainless steel, so that the surface can maintain a long-term passive state and stability. Therefore, it can improve the corrosion resistance and avoid various corrosion safety accidents in application. In general, due to the requirements to reduce the cost of 304 stainless steel square tube products and the provisions to improve the safety factor of 304 stainless steel square tube products, the technical application prospect of 304 stainless steel square tube passivation treatment will be very broad. Overview of the development trend of passivation treatment in China: passivation treatment was used earlier abroad, but it can be described as a development link in China. It is a prosperous metal surface treatment method in recent years with the continuous improvement of China's socio-economic development and export trade to consider the performance needs of commodities. Especially the passivation of stainless steel and iron. However, our company operates with passivation treatment and cleaning as key commodities. Moreover, in product research and development, people uphold the concept of "environmental protection, high efficiency, high quality, environmental protection and energy saving", and people have high-quality goods. Passivation treatment of 304 stainless steel square tube: after the metal material is solved by reducing substances, its etching rate is significantly lower than that before the original treatment, which is called passivation treatment of metal material.

For example, iron melts rapidly in dilute nitric acid, but the melting state is basically completely terminated in concentrated nitric acid; Aluminum is very unstable in dilute nitric acid, but aluminum vessels can be used to store concentrated nitric acid. This passivation treatment is called organic chemical passivation treatment.

Degreasing and deoiling: use the soap foot effect of alkali solution on vegetable oil to remove oil stains on the metal surface, so as to clean the surface. There are two kinds of pickling passivation: photocatalytic degreasing and organic chemical degreasing: also known as active or weak corrosion. It refers to the production and processing method of using organic chemistry or photocatalysis to remove the rust scale and ultra-thin air oxide film on the surface of steel parts in dilute corrosive aqueous solution, so as to make the metal surface of steel parts ubiquitous and active. It is called corrosion grinding and polishing: it refers to the selection of mechanical equipment or organic chemistry methods to carry out metal surface treatment on steel parts, So as to improve the surface flatness (surface roughness) and smoothness of steel parts.