301 stainless steel strip is a metastable austenitic stainless steel with complete austenitic structure under the condition of full solution. In stainless steel, 301 is the most easy to cold deformation and strengthening of steel, through cold deformation processing can make the strength and hardness of steel, and retain enough plastic, toughness, coupled with this steel in atmospheric conditions have good rust resistance, but in the reducing medium corrosion resistance is poor, in the acid alkali salt and other chemical media corrosion resistance is poor, so it is not recommended for corrosion harsh environment. 301 is mainly used in the cold processing state to withstand higher loads, but also want to reduce the weight of the equipment and do not rust equipment parts. In addition, the steel is easy to produce work hardening when hit by external forces, which can absorb more impact energy, and provide more reliable security for equipment and personnel.
301 is prone to work hardening during deformation and is used in places requiring higher strength
Chemical composition
301 stainless steel (video introduction) corresponding to the new Chinese brand :12Cr17Ni7 old brand 1Cr17Ni7.
Chemical composition %
C:≤0.15,
Si :≤1.0,
Mn :≤2.0,
Cr :16.0~18.0,
Ni :6.0-8.0,
S :≤0.03,
P :≤0.045
property
301 Stainless steel yield strength (N/mm2)≥205
Tensile strength ≥520 Elongation (%)≥40
Hardness HB ≤187 HRB≤90 HV ≤200
Density 7.93 g·cm-3
Specific heat c(20℃)0.502 J·(g·C)-1
Thermal conductivity λ/W(m·℃)-1 (at the following temperatures /℃)20 100 500 12.1 16.3 21.4
Linear expansion coefficient α/(10-6/℃) (at the following temperatures /℃) 20~100 20~200 20~300 20~400 16.0 16.8 17.5 18.1
Resistivity 0.73 Ω·mm2·m-1
Melting point 1398~1420℃
Mechanical property
Tensile strength σb (MPa):≥520
Conditional yield strength σ0.2 (MPa):≥205
Elongation δ5 (%):≥40
Section shrinkage ratio ψ (%):≥60
Hardness :≤187HB; ≤90HRB; ≤200HV
Heat treatment specification and metallographic structure
Heat treatment specification: Solution 1010~1150℃ fast cooling.
Metallographic structure: The structure is characterized by Austenitic type.
In the air or chemical corrosive medium can resist corrosion of a kind of high alloy steel, stainless steel is a beautiful surface and good corrosion resistance, do not have to go through plating and other surface treatment, and play the inherent surface properties of stainless steel, used in many aspects of steel, usually called stainless steel. Representative properties are 13 chromium steel, 18-8 chromium nickel steel and other high alloy steel. From the metallographic point of view, because stainless steel contains chromium and the surface of the formation of a very thin chromium film, this film is separated from the oxygen intrusion in the steel has a role in corrosion resistance. In order to maintain the corrosion resistance inherent in stainless steel, the steel must contain more than 12% chromium. 304 is a versatile stainless steel, which is widely used in the production of equipment and parts requiring good comprehensive properties (corrosion resistance and formability). 304 stainless steel is a grade of stainless steel produced according to ASTM standards in the United States. 304 is equivalent to 06Cr19Ni10 (0Cr18Ni9) stainless steel in China. 304 contains 18% chromium and 8% nickel. 301 is the most widely used stainless steel, heat-resistant steel. Used in food production equipment, Xitong chemical equipment, nuclear energy, etc. 304 stainless steel chemical composition specifications CSi Mn SRNi (nickel) MoSUS431 ≤0.08 ≤1.00 ≤2.00 ≤0.05 ≤0.03 18.00-20.00 8.25~10.50 -304 is 0Cr18Ni9. 301(17cr-7Ni-carbon) material: compared with 304 steel, Cr, Ni content is less, tensile strength and hardness increase during cold processing, non-magnetic, but magnetic after cold processing. Application: train, aircraft, conveyor belt, vehicle, bolt, spring, screen. Note :L stands for low carbon, such as 304L with lower carbon content than 304. H and S represent high temperature resistance, such as 310S than 310 high temperature resistance, 304H than 304 heat resistance.
Stainless steel knowledge
Stainless Steel (Stainless Steel) refers to steel that is resistant to weak corrosive media such as air, steam, water and chemical etching media such as acid, alkali, salt, etc., also known as stainless acid-resistant steel. In practical applications, the steel that is resistant to the corrosion of weak corrosive media is often called stainless steel, and the steel that is resistant to the corrosion of chemical media is called acid-resistant steel. Due to the difference in the chemical composition of the two, the former is not necessarily resistant to chemical medium corrosion, while the latter is generally stainless. The corrosion resistance of stainless steel depends on the alloying elements contained in the steel.
Folding type
Stainless steel is often divided into martensitic steel, ferritic steel, austenitic steel and so on. In addition, according to the composition can be divided into: chromium stainless steel, chromium nickel stainless steel and chromium manganese nitrogen stainless steel.
1. Ferritic stainless steel: 12%~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 kinds of stainless steel.
Belonging to this category are Crl7, Cr17Mo2Ti, Cr25, Cr25Mo3Ti, Cr28, etc. Because of its high chromium content, ferritic stainless steel has good corrosion resistance and oxidation resistance, but its mechanical properties and process properties are poor, and it is mostly used for acid-resistant structures with little force and for antioxidant steel. This kind of steel can resist the corrosion of atmosphere, nitric acid and brine solution, and has the characteristics of high temperature oxidation resistance, low thermal expansion coefficient, etc., used in nitric acid and food factory equipment, and can also make parts that work at high temperatures, such as gas turbine parts.
2, austenitic stainless steel: chromium content is more than 18%, but also contains about 8% nickel and a small amount of molybdenum, titanium, nitrogen and other elements. Good overall performance, can resist a variety of media corrosion. The common grades of austenitic stainless steel are 1Cr18Ni9, 0Cr19Ni9 and so on. wC< of 0Cr19Ni9 steel; 0.08%, marked with "0" in the steel number. This kind of steel contains a large amount of Ni and Cr, so that the steel is austenitic at room temperature. This kind of steel has good plasticity, toughness, weldability and corrosion resistance, corrosion resistance in oxidizing and reducing media are good, used to make acid resistant equipment, such as corrosion resistant containers and equipment lining, transportation pipes, nitric acid resistant equipment parts. Austenitic stainless steel generally adopts solid solution treatment, that is, the steel is heated to 1050~1150 ° C, and then water cooling to obtain single-phase austenitic structure.
3, austenite-ferrite duplex stainless steel: both austenitic and ferritic stainless steel advantages, and has superplasticity.
Stainless steel with about half austenitic and half ferritic structure. In the case of low C, the Cr content is 18% to 28%, and the Ni content is 3% to 10%. Some steels also contain Mo, Cu, Si, Nb, Ti, N and other alloying elements. This kind of steel has the characteristics of austenitic and ferritic stainless steel, compared with ferritic, higher plasticity, toughness, no room temperature brittleness, intergranular corrosion resistance and welding performance are significantly improved, while also maintaining the ferritic stainless steel 475℃ brittleness and high thermal conductivity, with superplasticity and other characteristics. Compared with austenitic stainless steel, it has higher strength and higher resistance to intergranular corrosion and chloride stress corrosion. Duplex stainless steel has excellent pitting resistance and is also a nickel-free stainless steel.
4, martensitic stainless steel: high strength, but poor plasticity and weldability.
The commonly used grades of martensitic stainless steel are 1Cr13, 3Cr13, etc., because of the high carbon content, it has higher strength, hardness and wear resistance, but the corrosion resistance is slightly poor, and it is used for some parts with higher mechanical properties and general corrosion resistance requirements, such as springs, turbine blades, hydraulic press valves, etc. This kind of steel is used after quenching and tempering treatment.
Stainless steel action
Stainless steel does not cause corrosion, pitting, rust or wear. Stainless steel is also one of the strongest materials in building metal materials. Because stainless steel has good corrosion resistance, it enables structural components to permanently maintain the integrity of the engineering design. Chromium stainless steel also combines mechanical strength and high extensibility, and is easy to process and manufacture parts to meet the needs of architects and structural designers
Folding typical use
Most of the use requirements are to maintain the original appearance of the building for a long time. When determining the type of stainless steel to be selected, the main consideration is the required aesthetic standards, the corrosiveness of the local atmosphere and the cleaning system to be used.
However, other applications are increasingly simply seeking structural integrity or impermeability. For example, the roofs and side walls of industrial buildings. In these applications, the owner's construction cost may be more important than aesthetics, and the surface is not very clean.
304 stainless steel works quite well in dry indoor environments. However, in rural and urban areas, if you want to maintain its appearance outdoors, it needs to be cleaned frequently. In heavily polluted industrial areas and coastal areas, the surface will be very dirty and even rust. However, to obtain the aesthetic effect in the outdoor environment, it is necessary to use nickel-containing stainless steel. Therefore, 304 stainless steel is widely used in curtain walls, side walls, roofs and other architectural purposes, but in the industrial or Marine atmosphere with serious erosion, it is best to use 316 stainless steel.
Stainless steel sliding door
People have fully recognized the advantages of using stainless steel in structural applications. Several design guidelines include 304 and 316 stainless steel. Because "duplex" stainless steel 2205 has combined good atmospheric corrosion resistance with high tensile strength and elastic limit strength, this steel is also included in the European guidelines.
Product shape
In fact, stainless steel is manufactured in all standard metal shapes and sizes, and there are many special shapes. The most commonly used products are made of sheet and strip steel, and special products are also made of medium and thick plates, for example, the production of hot rolled structural steel and extruded structural steel. There are also round, oval, square, rectangular and hexagonal welded pipe or seamless steel pipe and other forms of products, including profiles, bars, wires and castings.
Folded surface state
As will be discussed later, a variety of different commercial finishes have been developed to meet the aesthetic requirements of architects. For example, the surface can be highly reflective or dull; May be glossy, polished or embossed; It can be colored, colored, electroplated or etched with patterns on the surface of stainless steel, and can also be drawn to meet the various requirements of designers for appearance.
Keeping the surface is easy. Only occasional rinsing will remove dust. Due to its good corrosion resistance, it is also easy to remove surface scribing contamination or similar other surface contamination.
