Stainless steel plate is generally a general term for stainless steel plate and acid-resistant steel plate.
Introduced at the beginning of this century, the development of stainless steel plate has laid an important material and technical foundation for the development of modern industry and scientific and technological progress.
There are many types of stainless steel plates with different properties. It has gradually formed several categories in the development process.
Organizational structure classification
According to the structure, it is divided into four categories: austenitic stainless steel, martensitic stainless steel (including precipitation hardening stainless steel), ferritic stainless steel, and austenitic plus ferrite duplex stainless steel. According to the main chemical composition in the steel plate or some characteristic elements in the steel plate, it is divided into chromium stainless steel plate, chromium-nickel stainless steel plate, chromium-nickel-molybdenum stainless steel plate, low-carbon stainless steel plate, high-molybdenum stainless steel plate, high-purity stainless steel plate, etc. According to the performance characteristics and uses of steel plates, it is divided into nitric acid-resistant stainless steel plates, sulfuric acid-resistant stainless steel plates, pitting-resistant stainless steel plates, stress corrosion-resistant stainless steel plates, and high-strength stainless steel plates.
Classification of functional characteristics
According to the functional characteristics of the steel plate, it is divided into low temperature stainless steel plate, non-magnetic stainless steel plate, free-cutting stainless steel plate, superplastic stainless steel plate, etc. The commonly used classification method is to classify according to the structural characteristics of the steel plate, the chemical composition characteristics of the steel plate and the combination of the two. Generally divided into martensitic stainless steel, ferritic stainless steel, austenitic stainless steel, duplex stainless steel and precipitation hardening stainless steel, etc. or divided into two categories: chromium stainless steel and nickel stainless steel. Wide range of uses Typical uses: pulp and paper equipment heat exchangers, mechanical equipment, dyeing equipment, film processing equipment, pipelines, exterior materials for buildings in coastal areas, etc.
The stainless steel plate has a smooth surface, high plasticity, toughness and mechanical strength, and is resistant to corrosion by acids, alkaline gases, solutions and other media. It is an alloy steel that does not rust easily, but not absolutely rust-free.
Stainless steel has a similar resistance to general corrosion as the unstable Nichrome 304. Prolonged heating in the temperature range of chromium carbide degrees may affect Alloys 321 and 347 in harsh corrosive media. Mainly used in high temperature applications, which require strong resistance to sensitization of the material to prevent intergranular corrosion at lower temperatures.
High temperature oxidation resistance
Stainless steel plates are all resistant to high temperature oxidation, however, the oxidation rate will be affected by inherent factors such as exposure environment and product form.
The overall heat transfer coefficient of a metal depends on other factors besides the thermal conductivity of the metal. In most cases, the heat dissipation coefficient of the film, the scale and the surface condition of the metal. Stainless steel keeps surfaces clean, so it conducts heat better than other metals with higher thermal conductivity. Liaocheng Suntory Stainless provides 8. Technical standards for stainless steel plates High-strength stainless steel plates with excellent corrosion resistance, bending workability, toughness of welded parts, and stamping workability of welded parts and their manufacturing methods. Specifically, it contains C: 0.02% or less, N: 0.02% or less, Cr: 11% or more but less than 17%, appropriate content of Si, Mn, P, S, Al, Ni, and satisfies 12≤Cr Mo 1.5Si≤ 17. The stainless steel plate with 1≤Ni 30(CN) 0.5(Mn Cu)≤4, Cr 0.5(Ni Cu) 3.3Mo≥16.0, 0.006≤CN≤0.030 is heated to 850～1250℃, and then heated to 1℃/s The above cooling rate cooling heat treatment. In this way, it can be a high-strength stainless steel plate with a structure containing more than 12% martensite by volume, high strength of more than 730MPa, corrosion resistance and bending performance, and excellent toughness of the welding heat-affected zone. Reuse of Mo, B, etc., can significantly improve the stamping performance of the welded part.
The flame of oxygen and gas cannot cut stainless steel because stainless steel is not easily oxidized.
Carbon (C): 1. Improve the deformation resistance and tensile strength of the blade; 2. Enhance the hardness and improve the wear resistance.
Chromium (Cr): 1. Enhance hardness, tensile strength and toughness; 2. Prevent wear and corrosion.
Cobalt (Co): 1. Increases hardness and strength so that it can withstand high temperature quenching; 2. Used in more complex alloys to enhance certain individual properties of other elements.
Copper (Cu): 1. Enhance corrosion resistance; 2. Enhance wear resistance.
Manganese (Mn): 1. Increase hardenability, wear resistance and tensile strength; 2. Take oxygen away from molten metal by separation oxidation and separation vaporization; 3. When added in large quantities, increase hardness, but increase brittleness.
Molybdenum (Mo): 1. Enhance strength, hardness, hardenability and toughness; 2. Improve machinability and corrosion resistance.
Nickel (Ni): 1. Enhance strength, hardness and corrosion resistance.
Phosphorus (P): Enhances strength, machinability and hardness.
2. When the concentration is too large, it is easy to be brittle
Silicon (Si): 1. Enhances ductility; 2. Increases tensile strength; 3. Removes oxygen from molten metal by separation oxidation and separation vaporization.
Sulfur (S): Use in small amounts to improve machinability.
Tungsten (W): Increases strength, hardness and toughness.
Vanadium (V): Increases strength, hardness and shock resistance.
1. On the surface of stainless steel, there are deposits of dust or heterogeneous metal particles containing other metal elements. In humid air, the condensed water between the deposits and the stainless steel connects the two into a micro-battery, which triggers an electrochemical reaction. , the protective film is damaged, called electrochemical corrosion.
2. Organic juices (such as vegetables, noodle soup, sputum, etc.) adhere to the surface of stainless steel. In the presence of water and oxygen, organic acids are formed, and organic acids will corrode the metal surface for a long time.
3. The surface of stainless steel adheres to substances containing acids, alkalis and salts (such as alkali water and lime water splashing from the decoration walls), causing local corrosion.
4. In the polluted air (such as the atmosphere containing a large amount of sulfide, carbon oxide, nitrogen oxide), in the presence of condensed water, the formation of sulfuric acid, nitric acid, acetic acid liquid spots, causing chemical corrosion The above conditions can cause the protective film on the stainless steel surface. Damage causes rust.
The corrosion resistance of stainless steel mainly depends on its alloy composition (chromium, nickel, titanium, silicon, aluminum, manganese, etc.) and internal structure, and the main role is chromium. Chromium has high chemical stability and can form a passivation film on the steel surface to isolate the metal from the outside world, protect the steel plate from being oxidized, and increase the corrosion resistance of the steel plate. After the passivation film is destroyed, the corrosion resistance decreases.
Numbering and Representation
1.Use international chemical element symbols and national symbols to represent chemical components, and use Arabic letters to represent component content:
Such as: China, Russia 12CrNi3A
2.Use fixed-digit numbers to represent steel series or numbers; such as: the United States, Japan, 300 series, 400 series, 200 series.
3.The serial number is composed of Latin letters and sequences, which only indicate the purpose.
International stainless steel marking method
The American Iron and Steel Institute uses three digits to designate various standard grades of malleable stainless steel. in:
1. Austenitic stainless steels are marked with numbers in the 200 and 300 series.
2. Ferritic and martensitic stainless steels are represented by numbers in the 400 series. For example, some of the more common austenitic stainless steels are designated 201, 304, 316 and 310.
3. Ferritic stainless steels are marked with 430 and 446, and martensitic stainless steels are marked with 410, 420 and 440C, duplex (austenite-ferrite).
4. Stainless steel, precipitation hardening stainless steel, and high alloys with less than 50% iron are usually named by patent names or trademarks.
The selection of stainless steel plate should consider the operating conditions, such as manual operation or automatic operation, the performance and type of the hot press, and the quality requirements of the pressed material such as hardness and gloss. Economic accounting should also be considered. Each time a newly polished steel plate is required, the number of times that a decorative plate of a slow quality can be produced.
In addition, when choosing the most reasonable thickness of the steel plate, its service time, quality and stiffness should be considered, and at the same time, the strength requirements of the plate when it is pressed; thermal conductivity; pressure distribution;
If the thickness of the steel plate is not enough, it is easy to bend, which will inevitably affect the production of decorative panels. If the thickness is too large and the steel plate is too heavy, it will not only increase the cost of the steel plate, but also bring unnecessary difficulties to the operation. At the same time, the allowance that should be left when the stainless steel plate is processed or used should also be considered. The thickness of the copper plate is not absolutely consistent, but the thickness of the same steel plate should be as consistent as possible. Generally, the thickness tolerance of a medium-sized saw plate is 0.05 to 0.15 mm. If the requirements are too strict, the grinding cost will also increase accordingly. Generally, it is a steel plate with high tensile strength and high hardness. The greater the resistance to mechanical damage, the longer the durability, but the cost of grinding and processing is also relatively high.
(1) Thin plate (0.2mm-4mm)
(2) Medium plate (4mm-20mm)
(3) Thick plate (20mm-60mm)
(4) Extra thick plate (60-115mm)
By production method
(1) Hot rolled steel sheet
(2) Cold rolled steel sheet
By surface features
Outline of the manufacturing method
Hot rolled to specified thickness
Uses that do not require a glossy finish
Cold rolled and then heat treated and pickled
General purpose, deep-drawn material
Shine stronger than NO.2D
NO.2D treatment followed by a final light cold roll on polishing rolls
Shiny as a mirror
No standard, but usually bright annealed surface finish with high surface reflectivity.
Building materials, kitchen utensils
Abrasive belt with 100 to 200# (units) of mainstay grain, for grinding
Building materials, kitchen utensils
Polished surfaces obtained by grinding with 150-180# abrasive belts
Grinding with 240# abrasive belt
Extremely fine grinding
Grinding with a 320# abrasive belt
Glossy close to BA
Polishing with a 400# polishing wheel
General, building materials, kitchenware
The material with the appropriate grains is subjected to hairline grinding (150-240#), which has a large number of main particles.
Buildings, building materials
Close to mirror grinding
Grinding with 600# rotary polishing wheel
Fine art, decorative
Mirror grinding with polishing wheel
Reflective mirror, for decoration
(1) Bridge steel plate
(2) Boiler steel plate
(3) Shipbuilding steel plate
(4) Armor steel plate
(5) Automobile steel plate
(6) Roof steel plate
(7) Structural steel plate
(8) Electrical steel sheet (silicon steel sheet)
(9) Spring steel plate
(10) Solar panels (Hairui Special Steel)
(11) Other Japanese grades commonly found in ordinary and mechanical structural steel plates.
Organized by steel grade
(1) Austenitic type
(2) Austenite-ferrite type
(3) Ferrite type
(4) Martensitic type