202 stainless steel is a popular multifunctional alloy known for its excellent composition and performance characteristics. It is mainly composed of chromium, nickel, manganese and nitrogen, and has excellent corrosion resistance and oxidation resistance, making it ideal for a variety of industrial and household applications. This austenitic stainless steel also has excellent toughness, strength and formability, allowing it to be easily machined into different shapes and structures. In addition, the addition of nitrogen enhances its mechanical properties, making it more durable and stronger than other stainless steel grades. With so many features in combination, 202 stainless steel has excellent performance in different environments, making it a reliable choice for a variety of buildings, kitchenware, automotive parts, and many other uses.

Some of the main advantages of 316 stainless steel:

Heat and cold resistance: 316 stainless steel performs well at temperatures up to 800°C.

Rust and wear resistance: Compared with other stainless steel grades, 316 has excellent rust and wear resistance.

Corrosion resistance: Adding molybdenum to 316 stainless steel can improve its resistance to acid, alkali and chloride pitting.

Easy to form and weld: 316 stainless steel is easy to weld with TIG or MIG welding and does not require post-weld annealing. After annealing, it is non-magnetic. 316 stainless steel can also be easily formed by braking or rolling molding.

Durability: It has a tensile strength of 515 MPa and maintains its corrosion resistance with minimal maintenance.

Hygiene: This grade of stainless steel is ideal for hygienic applications as it is easy to clean and disinfect.

Sustainability: 316 stainless steel is 100% recyclable.

Decarbonization is not only related to temperature, but also depends on the type of metal or alloy, and depends on the heating medium. For example, silicon steel is easy to decarbonize, stainless steel is not easy to decarbonize, heat-resistant steel is not easy to decarbonize, if it is a reducing medium, you heat to the melting state will not decarbonize, if it is an oxidizing medium, it mainly depends on the level of oxidation, if it is heated in the air, the decarbonization situation is more difficult to say, only specific problem specific analysis, general carbon steel about 570 Degree produces strong oxidation decarburization.

Decarbonization or not has a lot to do with chemical composition, heating temperature, holding time, the existence form of carbon in the metallographic organization, and environmental atmosphere. Chemical composition alone cannot determine the heating temperature required to decarbonize the surface of the material.

The surface decarburization of steel materials is related to the carbon content or carbon equivalent. Taking 60Si2Mn as an example, the decarburization sensitive zone is about 1150-1250 degrees.

Decarbonization is also related to the heating atmosphere and heating time.

Another thing to consider is that oxidation and decarbonization generally exist at the same time, if the oxidation rate is greater than decarbonization, then even in the high temperature zone will not cause material decarbonization, but the surface oxide thickness increases. 35CrMo is generally used for the production of high-strength fasteners, which generally requires the spinning temperature not to exceed 880 degrees, the cooling speed in the range of 0.8-0.85 degrees /s, and the decarburization layer can be controlled between (0.2-0.4)D%. This decarbonized layer is tolerable and subsequent cold heading and mechanical properties can be guaranteed.

Due to the different use of each product, its processing technology and raw material quality requirements are also different. Generally speaking, stainless steel products are different, its requirements for raw material thickness tolerances are also different, such as class II tableware and thermos cups, etc., thickness tolerances are generally higher, of -3~5%, and a class of tableware thickness tolerances generally require -5%, steel pipe requirements -10%, hotel freezer thickness tolerances are -8%. Dealers' requirements for thickness tolerances are generally between -4% and 6%. At the same time, the different sales of products at home and abroad will also lead to the different requirements of customers on the thickness tolerance of raw materials. Generally, customers of export products have higher thickness tolerance requirements, while domestic enterprises have relatively low thickness tolerance requirements (mostly due to cost considerations), and some customers even require -15%.

DDQ (deep drawing quality) material: refers to the material used for deep drawing (drawing), that is, the soft material that we say, the main characteristics of this material are high elongation (≧53%), low hardness (≦170%), the internal grain grade is between 7.0 and 8.0, and the deep drawing performance is excellent. Many enterprises that produce thermos bottles and POTS, the processing ratio of their products (BLANKING SIZE/ product diameter) is generally relatively high, and their processing ratios reach 3.0, 1.96, 2.13, and 1.98, respectively. SUS304DDQ materials are mainly used for these products that require a higher processing ratio, of course, products with a processing ratio of more than 2.0 generally need to be completed after several stretches. If the extension of raw materials can not be reached, the phenomenon of cracking and pulling through is easy to occur in the processing of deep-drawn products, which affects the qualified rate of finished products, and of course increases the cost of manufacturers;

② General materials: Mainly used for materials other than DDQ purposes, this material is characterized by relatively low elongation (≧45%), relatively high hardness (≦180HB), internal grain size grade between 8.0 and 9.0, compared with DDQ materials, its deep drawing performance is relatively poor, it is mainly used for products that can be obtained without stretching. Like a type of tableware spoon, spoon, fork, electrical appliances, steel pipe use. However, it has an advantage compared with DDQ materials, that is, the BQ property is relatively good, mainly due to its slightly higher hardness.

Stainless steel sheet is a low price material, but customers have very high requirements for its surface quality. Stainless sheet in the production process will inevitably appear a variety of defects, such as scratches, pitting, sand holes, dark lines, creases, pollution, etc., so that its surface quality, such as scratches, creases and other defects are not allowed to appear in advanced materials, and pitting, sand holes this defect in the spoon, spoon, fork, production is also never allowed, because it is difficult to throw it away when polishing. It is necessary to determine the surface quality level according to the degree and frequency of various defects on the surface, so as to determine the product grade.