1. Weldability: Different product uses have different requirements for welding performance. Category I tableware generally does not require welding performance, even for some pot-type companies. But most products require raw materials with good welding performance, such as second-class tableware, thermos cups, steel pipes, water heaters, water dispensers, etc.
2. Corrosion resistance: Most stainless steel products require good corrosion resistance, such as Class I and II tableware, kitchen utensils, water heaters, drinking fountains, etc. Some foreign businessmen also conduct corrosion resistance tests on their products: use NACL aqueous solution heated to Boil, pour out the solution after some time, wash and dry, and weigh the weight loss to determine the degree of corrosion (Note: When polishing the product, the Fe component in the emery cloth or sandpaper will cause rust spots to appear on the surface during the test)
3. Polishing performance: In today's society, stainless steel products generally go through the polishing process during production. Only a few products, such as water heaters and water dispenser linings, do not require polishing. Therefore, this requires the raw material to have good polishing performance. The factors that affect polishing performance mainly include the following points:
①Surface defects of raw materials. Such as scratches, pitting, pickling, etc.
② Raw material problem. If the hardness is too low, it will be difficult to polish during polishing (poor BQ properties). Moreover, if the hardness is too low, the orange peel phenomenon will easily appear on the surface during deep drawing, thus affecting the BQ properties. BQ with high hardness is relatively good.
③For products that have undergone deep drawing, small black spots and RIDGING will appear on the surface in areas with great deformation, thus affecting BQ properties.
4. Heat resistance: Heat resistance means that stainless steel can still maintain its excellent physical and mechanical properties under high temperatures.
Effect of Carbon: Carbon is strongly formed and stable in austenitic stainless steels. Elements that determine austenite and expand the austenite zone. The ability of carbon to form austenite is about 30 times that of nickel. Carbon is an interstitial element and can significantly improve the strength of austenitic stainless steel through solid solution strengthening. Carbon can also improve the stress-corrosion resistance of austenitic stainless steel in highly concentrated chlorides (such as 42% MgCl2 boiling solution).
5. Corrosion resistance: When the number of chromium atoms in the steel is not less than 12.5%, the electrode potential of the steel can suddenly change from negative potential to positive electrode potential. Prevent electrochemical corrosion.