Finding the best quality steel productsJUL.11,2022
How ronggangpipe.com is the leadingsteel sellers?JUL.11,2022
Carbon Steel Pipe Buying GuideJUL.11,2022
What is the quality of stainless steel?JUL.05,2022
Ronggangpipe.com”: The Leading steel products suppliersJUN.13,2022
Ronggangpipe.com: NO.1 Steel sellers & manufacturersJUN.13,2022
How To Buy quality Carbon Steel Pipes?JUN.13,2022
What is the difference in Steel and Stainless Steel?JUN.23,2022
What’s the difference between Steel & Stainless Steel?JUN.15,2022
Why does stainless steel not rust?JUN.07,2022
Introduction and classification of stainless steel today
All metals react with oxygen in the atmosphere to form an oxide film on the surface. Unfortunately, the iron oxide formed on ordinary carbon steel continues to oxidize, causing the corrosion to continue to expand and eventually forming holes. You can use paint or oxidation-resistant metals (such as zinc, nickel, and chromium) for electroplating to ensure the surface of carbon steel, but, as people know, this protection is only a thin film. If the protective layer is damaged, the steel below will begin to rust.
Steel that is resistant to weak corrosive media such as air, steam, and water, and chemically corrosive media such as acids, alkalis, and salts. Also known as stainless acid-resistant steel. In practical applications, steel that is resistant to corrosion by weak corrosive media is often called stainless steel, and steel that is resistant to chemical media is called acid-resistant steel. Due to the difference in chemical composition between the two, the former is not necessarily resistant to corrosion by chemical media, while the latter is generally non-corrosive. The corrosion resistance of stainless steel depends on the alloying elements contained in the steel. Chromium is the basic element for the corrosion resistance of stainless steel. When the chromium content in the steel reaches about 1.2%, the chromium interacts with the oxygen in the corrosive medium to form a very thin oxide film (self-passivation film) on the surface of the steel. , Can prevent further corrosion of the steel matrix. In addition to chromium, commonly used alloying elements include nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., to meet the requirements of various uses for the structure and performance of stainless steel.
Stainless steel is usually divided into:
1. Ferritic stainless steel. Containing 12% to 30% chromium. Its corrosion resistance, toughness, and weldability increase with the increase of chromium content, and its resistance to chloride stress corrosion is better than other types of stainless steel. 2, austenitic stainless steel. The chromium content is more than 18%, and it also contains about 8% nickel and a small amount of molybdenum, titanium, nitrogen, and other elements. Good overall performance, resistant to corrosion by various media.
3, austenitic-ferritic duplex stainless steel. It has the advantages of austenitic and ferritic stainless steel and has superplasticity.
4. Martensitic stainless steel. High strength, but poor plasticity and weldability.
5. Precipitation hardening stainless steel. It has good formability and good weldability and can be used as an ultra-high-strength material in the nuclear industry, aviation, and aerospace industries. According to the composition, it can be divided into Cr series (SUS400), Cr-Ni series (SUS300), Cr-Mn-Ni (SUS200), and precipitation hardening series (SUS600).