Materials of Stainless Steel

December 7, 2018


     Due to the different uses of each product, the quality requirements of the processing technology and raw materials are also different. Generally speaking, the difference in the thickness of stainless steel products requires different thickness tolerances. For example, the second type of tableware and vacuum cups, the thickness tolerance is generally required to be -3 to 5%, and the thickness tolerance of a type of tableware is generally required - 5%, the steel pipe category requires -10%, the hotel's freezer material thickness tolerance requirement is -8%, the dealer's thickness tolerance requirements are generally between -4% and 6%. At the same time, the difference between the internal and external sales of the products will also lead to different requirements for the thickness tolerance of the raw materials. General export product customers have higher thickness tolerance requirements, while domestic sales companies have relatively low thickness tolerance requirements (mostly due to cost considerations), and some customers even require -15%.


    1DDQ (deep drawing quality) material: refers to the material used for deep drawing (rushing), which is what everyone calls soft material. The main feature of this material is the high elongation (≧53%), hardness Low (≦170%), internal grain grade between 7.0 and 8.0, deep draw performance is excellent. Many companies producing thermos and pots generally have higher processing ratios (BLANKING SIZE/product diameter), and their processing ratios are 3.0, 1.96, 2.13, and 1.98, respectively. SUS304DDQ materials are mainly used for these products with higher processing ratios. Of course, products with a processing ratio of more than 2.0 generally need to be stretched several times to complete. If the raw material is not extended, the product is prone to cracks and punctures when processing deep drawn products, which affects the pass rate of the finished product, and of course increases the cost of the manufacturer;


     2 General materials: mainly used for materials other than DDQ. This material is characterized by relatively low elongation (≧45%), relatively high hardness (≦180HB), and internal grain size of 8.0~9.0. In comparison with DDQ materials, its deep-drawing performance is relatively poor. It is mainly used for products that can be obtained without stretching, such as spoons, spoons, forks, electrical appliances, and steel pipes for a class of tableware. However, it has an advantage over DDQ material, that is, BQ is relatively good, mainly due to its slightly higher hardness.
Stainless steel sheets are a low-cost material, but customers have very high surface quality requirements. Stainless steel sheets inevitably have various defects in the production process, such as scratches, pitting, sand holes, dark lines, creases, pollution, etc., so that their surface quality, such as scratches, creases, etc. are high-grade materials. It is not allowed to appear, and the defects such as pitting and sand hole are never allowed in the spoon, spoon, fork, and production, because it is difficult to throw it away during polishing. It is necessary to determine the quality level of the surface based on the degree and frequency of occurrence of various defects to determine the product grade.