Steel is not a single product. There are more than 3,500 different grades of steel with many different physical, chemical, and environmental properties.Approximately 75% of modern steels have been developed in the past 20 years. According to the American Iron and Steel Institute (AISI), steel can be broadly categorized into four groups based on their chemical compositions:
1. Carbon Steel
2. Alloy Steel
3. Stainless Steels
4. Tool Steels
Carbon Steel: The carbon content is about 0.05% to 0.70%, and the individual amount can be as high as 0.90%. Can be divided into two types of ordinary carbon structural steel and high quality carbon structural steel. It has many uses and a large amount of use. It is mainly used in railways, bridges, and various construction projects. It manufactures various metal components subjected to static loads and mechanical parts and general welded parts that do not require heat treatment.
Alloy Steel: iron-carbon alloy composed of an appropriate amount of one or more alloying elements added to ordinary carbon steel. Depending on the added elements and appropriate processing techniques, special properties such as high strength, high toughness, wear resistance, corrosion resistance, low temperature resistance, high temperature resistance and non-magnetic properties can be obtained.
Stainless steel: refers to steel that is resistant to weak corrosive media such as air, steam, water, and chemically etched media such as acid, alkali, salt, etc., also known as stainless acid-resistant steel. In practical applications, steel that is resistant to weak corrosive media is often referred to as stainless steel, while steel that is resistant to chemical media is referred to as acid-resistant steel. Due to the difference in chemical composition between the two, the former is not necessarily resistant to chemical media corrosion, while the latter generally has rust. The corrosion resistance of stainless steel depends on the alloying elements contained in the steel.
Tool steel: steel used to make cutting tools, gauges, molds and wear tools. Tool steels have high hardness and high hardness and red hardness at high temperatures, as well as high wear resistance and proper toughness. Tool steels are generally classified into carbon tool steels, alloy tool steels, and high speed tool steels.