Galvanized pipe processing after plating process including pretreatment, plating and electroplating processing. The electroplating process depends on the quality of coating materials and plating process is influenced by side impact beams many factors. The following six factors summarized as follows:
1, zinc content. 2, sodium hydroxide. 3, iron content. 4, brightener. 5, and temperature. 6, cathode movement speed.
If you choose to ordinary steel tube, you buy steel tube and you receive pole will have a lot of error in determining the type and specification. Even in different parts of the steel tube, inner diameter or wall thickness, can make a big difference. Throughout the application process, this pipe Will no doubt produce a lot of difficulties. But the precision steel tube is different. This kind of steel pipe specifications are very strict.
Precision steel tube, although impossible, pipe specifications are accord with actual specifications per level. But precision steel tube can control the measurement error in small a category. In general, this is not easy to determine error, more than two standard of the enterprise Is enough, for most fields.
As you all know, steel pipe in outdoor in the long run, or what is the friction, air oxidation layer on the surface of the stainless steel plate will be destroyed, then in the damp cold gas oxidation rust in the natural side impact door beams environment. Therefore, steel pipes should be placed in a sealed area as much as possible The domain. And precision steel pipe has the advantage, because the surface is not easy to oxidation, the composition of precision steel tube of raw materials is inseparable. Steel pipe is produced on the surface of a thin, strong, is exquisite, the stability of the rich chromium oxide film air, can be avoided Oxygen molecules to penetrate and air oxidation, antirust ability to work. Weak corrosion resistance of precision steel tube that transition film part for self-excited oscillation, reflected by the pitting corrosion holes will form of chlorine ion content, strong corrosion solution of similar from And to speed up the corrosion. In addition, the stress corrosion cracking of stainless steel plate internal damage transition film on the surface of the stainless steel plate. Therefore, precision steel pipe surface should be clean and keep in the corresponding level, to increase the service life.
What is the cause of the stainless steel pipe crack? Relevant experts to test the crack of steel pipe, the water quality of steel pipe are analyzed.
Results: the crack as stress corrosion cracking; When used in 60 ~ 120 ℃ temperature environment, the chloride ion content and total hardness steel pipe water quality exceeds bid badly is the stainless steel tube in the stress of the main causes of stress corrosion fracture.
Should be under the influence of the environment corrosion cracking caused by metal.
Occurrence crack must have two conditions. There is stress and corrosive medium.
Stress corrosion is one of the important failure forms of aluminium coated steel tube stainless steel, the typical stress corrosion crack in dendritic. The stress corrosion of stainless steel under different corrosion medium environment behavior research is one of the important contents of stainless steel corrosion research. Combined with practical examples, this paper stated Stress corrosion cracking of stainless steel process, and the damage to equipment, analyzes its reasons, find out the reasonable ways to avoid stress corrosion cracking.