Characteristics of Alloy Steel Plate or Sheet

With the development of science, technology and industry, higher requirements are put forward for materials, such as higher strength, resistance to high temperature, high pressure, low temperature, corrosion resistance, wear and other special physical and chemical properties. To meet the requirements, alloy Steel Plates appeared.
The Steel Plate is flat, rectangular and can be directly rolled or cut from wide steel strips.
The steel plate is divided according to the thickness, the thin steel plate is less than 4 mm (the thinnest is 0.2 mm), the thick steel plate is 4-60 mm, and the extra-thick steel plate is 60-115 mm.
Steel Sheets are divided into hot-rolled and cold-rolled according to rolling. The width of the thin plate is 500~1500 mm; the width of the thick sheet is 600~3000 mm. Sheets are classified according to steel types, including ordinary steel, high-quality steel, alloy steel, spring steel, stainless steel, tool steel, heat-resistant steel, bearing steel, silicon steel and industrial pure iron sheet, etc.; Enamel plate, bulletproof plate, etc.; According to the surface coating, there are galvanized sheet, tin-plated sheet, lead-plated sheet, plastic composite steel plate, etc.
The steel grade of the thick steel plate is generally the same as that of the thin steel plate. In terms of products, in addition to bridge steel plates, boiler steel plates, automobile steel plates, pressure vessel steel plates, and multi-layer high-pressure vessel steel plates, which are pure thick plates, some varieties of steel plates such as automobile girder steel plates (2.5-10 mm thick), patterned steel plates, etc. Steel plates (2.5-8 mm thick), stainless steel plates, heat-resistant steel plates and other varieties are intersected with thin plates.
In addition, the steel plate also has a material, not all steel plates are the same, the materials are different, and the places where the steel plates are used are also different.
With the development of science, technology and industry, higher requirements are put forward for materials, such as higher strength, high temperature, high pressure, low temperature, corrosion resistance, wear resistance and other special physical and chemical properties. fulfil requirements.
The performance of carbon steel mainly has the following shortcomings:
(1) Low hardenability Under normal circumstances, the maximum hardenable diameter of carbon steel water quenching is only 10mm-20mm.
(2) The strength and yield strength are relatively low. For example, the σs of ordinary carbon steel Q235 steel is 235MPa, while the σs of low alloy structural steel 16Mn is more than 360MPa. The σs/σb of 40 steel is only 0.43, which is much lower than that of alloy steel.
(3) Poor tempering stability Due to the poor tempering stability, when carbon steel is quenched and tempered, a lower tempering temperature is required to ensure higher strength, so that the toughness of the steel is low; in order to ensure better Toughness, and the strength is low when the high tempering temperature is used, so the comprehensive mechanical properties of carbon steel are not high.
(4) Can not meet the requirements of special properties Carbon steel is often poor in terms of oxidation resistance, corrosion resistance, heat resistance, low temperature resistance, wear resistance and special electromagnetic properties, and cannot meet the needs of special performance properties.
By alloying element content
Low alloy steel (total alloy elements less than 5%), medium alloy steel (total alloy elements from 5% to 10%), high alloy steel (total alloy elements above 10%).
By alloying element composition
Chromium steel (Cr-Fe-C), chromium-nickel steel (Cr-Ni-Fe-C), manganese steel (Mn-Fe-C), silicon manganese steel (Si-Mn-Fe-C).
According to the normalized or as-cast structure of the small sample
Pearlitic steel, martensitic steel, ferritic steel, austenitic steel, ledeburite steel.
By use
Alloy structural steel, alloy tool steel, special performance steel.