Stainless steel 

To put it simply, stainless steel is not easy to rust steel, in fact, a part of stainless steel, both rust, and acid (corrosion resistance).Stainless steel's rust and corrosion resistance are due to the composition of a chrome-rich oxide film (passivation film) on its surface.This rust resistance is relative to corrosion resistance.The experimental results show that the corrosion resistance of steel in the atmosphere, water and other weak medium and nitric acid oxidation medium, with the addition of chromium water content in steel and progress, when the chromium content reached a certain percentage, steel corrosion resistance attack sudden change, that is, from easy to rust to rust, not corrosion resistance to corrosion.There are many ways to classify stainless steel.According to the arrangement structure classification at room temperature, there are martensite, austensite, ferrite and duplex stainless steel;According to the primary chemical composition classification, basically can be divided into chromium stainless steel and chromium nickel stainless steel two systems;According to the use of stainless steel nitric acid resistance, resistance to sulfuric acid stainless steel, seawater resistance stainless steel, etc., according to the type of corrosion resistance can be divided into pitting stainless steel, stress corrosion resistance stainless steel, intercrystalline corrosion resistance stainless steel;According to function characteristic classification can be divided into non-magnetic stainless steel, free cutting stainless steel, low temperature stainless steel, high strength stainless steel and so on.Because stainless steel has outstanding corrosion resistance, formability, compatibility and in a very wide range of temperature in the strong patience and other series of characteristics, so in heavy industry, light industry, daily necessities occupation and building decoration and other occupations to obtain a wide range of applications.Austenitic stainless steel having an austenitic arrangement at room temperature.Steel with Cr about 18%, Ni 8%~10% and C about 0.1% has stable austenite arrangement.Austenitic chrome-nickel stainless steel contains the famous 18cr-8ni steel and on this basis, the addition of Cr, Ni content and participate in Mo, Cu, Si, Nb, Ti and other elements developed by the high cr-ni series of steel.Austenitic stainless steel is non-magnetic and has high resistance and plasticity, but the strength is low, it can not be strengthened through phase change, can only be strengthened through cold processing.Such as S, Ca, Se, Te and other elements, it has excellent cutting.This kind of steel in addition to oxidation resistance acid medium corrosion, if the element such as Mo, Cu also ability sulfuric acid, phosphoric acid and, acetic acid, urea corrosion.If the carbon content of this kind of steel is less than 0.03% or contains Ti and Ni, its intercrystalline corrosion resistance can be significantly improved.High silicon austenitic stainless steel has excellent corrosion resistance.Because of its comprehensive and outstanding induction function, austenitic stainless steel has been widely used in all walks of life. 

Stainless steel pipe

Stainless steel tube is a kind of hollow long round steel, mainly used in petroleum, chemical, medical, food, light industry, mechanical instruments and other industrial pipelines and mechanical structure components.In addition, in the same bending and torsional strength, the weight is lighter, so it is also widely used in the manufacture of mechanical parts and engineering structures.Also commonly used as furniture kitchenware.

process

Production process a of stainless steel seamless tube.Round steel preparation;B.Heating;C.Hot rolled piercing;D.Cutting head;E.Pickling.F.Grinding;G.Lubrication;H.Cold rolling process;I.Degreasing;J.Solid solution heat treatment;K.Straightening;L.Pipe cutting;M.Pickling.N.Finished product inspection.

The material classification

Stainless steel tubes can be divided into Cr series (400 series), Cr-Ni series (300 series), Cr- mn-ni series (200 series) and precipitated hardening series (600 series).200 series - chrome-nickel-manganese austenitic stainless steel 300 series - chrome-nickel austenitic stainless steel.

301-- good ductility, used for molding products.It can also be rapidly hardened by machining.Good weldability.Better wear resistance and fatigue strength than 304 stainless steel.

302-- corrosion resistance is the same as 304, and the strength is better due to the relatively high carbon content.

303-- adding a small amount of sulfur and phosphorus makes it easier to cut than 304.

304-- 18/8 stainless steel.GB brand number is 0Cr18Ni9.309 - better temperature resistance than 304.

316-- the second most widely used steel, after 304, is used in the food industry, the pharmaceutical industry and surgical equipment, adding molybdenum to give it a special anti-corrosion structure.Because it has a better resistance to chloride corrosion than 304 stainless steel tubes, it is also used as "Marine steel".SS316 is commonly used in nuclear fuel recovery plants.Grade 18/10 stainless steel tubes usually meet this application grade as well.

Model 321 - similar to 304 except that the risk of weld corrosion is reduced by the addition of titanium.

These stainless steel pipe grades are sold to a wide range of industries/markets, due to their overall corrosion resistance and good machinability:

* Chemical and petrochemical
* Power generation
* Renewable energy
* Pulp and Paper
* Process piping
* Pharmaceutical
* Food and beverage
* Oil and gas
* Mining
* Water/waste
* Marine