The characteristics of stainless steel sheeting

Corrosion-resistant stainless steel sheeting 

The majority of stainless steel rolled sheet products require excellent corrosion resistance. For instance, items such as tableware, kitchenware, water heaters, and water purifiers all fall into this category. Some foreign merchants even conduct corrosion resistance tests on these products: they heat a NaCl aqueous solution to boiling, wait for a period of time, then pour out the solution, clean and dry it, and weigh the weight loss to determine the degree of corrosion. When the atomic quantity of chromium in the steel is not less than 12.5%, it can cause a sudden change in the electrode potential of the steel, rising from a negative potential to a positive one, thereby preventing electrochemical corrosion. 

Weldable stainless steel sheeting 

The different uses of the products also lead to varying requirements for welding performance. The majority of products require the raw materials to have good welding performance, such as tableware of the second category, thermos cups, steel pipes, water heaters, and water dispensers, etc. 

Heat-resistant stainless steel sheeting 

Stainless steel can still maintain its excellent properties even when subjected to high temperatures during rolling. 

The influence of carbon: Carbon is a strongly forming and stable element in the rolling process of austenitic stainless steel, which forms austenite and expands the austenite zone. The ability of carbon to form austenite is approximately 30 times that of nickel. Carbon is an interstitial element and can significantly enhance the strength of austenitic stainless steel rolling through solid solution strengthening. Carbon can also improve the stress corrosion resistance of austenitic stainless steel rolling in high chloride solutions (such as 42% MgCl2 boiling solution). 

However, in the rolling process of austenitic stainless steel, carbon is often regarded as a harmful element. This is mainly because under certain conditions in the corrosion-resistant applications of stainless steel rolling (such as welding or heating at 450-850℃), carbon can react with chromium in the steel to form high-chromium Cr23C6 type carbon compounds, thereby causing local chromium depletion and reducing the corrosion resistance of the steel, especially the intergranular corrosion resistance. Therefore, some experimental studies also indicate that carbon can also increase the tendency of point corrosion in the rolling process of chromium austenitic stainless steel. Due to the harmful effect of carbon, not only should the carbon content be controlled as low as possible during the smelting and rolling process of austenitic stainless steel, but also during subsequent hot, cold processing and heat treatment processes, measures should be taken to prevent the increase of carbon on the surface of the rolled stainless steel and to avoid the precipitation of chromium-free carbides. 

Polished stainless steel sheeting 

In today's society, stainless steel rolled sheet products are generally subjected to the polishing process during production. Only a few products, such as water heaters and water dispenser inner tanks, do not require polishing. Therefore, it is necessary for the raw materials to have excellent polishing performance. The factors affecting the polishing performance mainly include the following points: 

①Surface defects of the raw materials. Such as scratches, blemishes, excessive acid washing, etc. 

② Raw material quality issue. The hardness is too low, making it difficult to achieve a smooth finish during polishing (poor BQ property). Moreover, with such low hardness, the surface is prone to develop an orange peel effect during deep stretching, thereby affecting the BQ property. Materials with higher hardness generally have better BQ properties. 

③ For products that have undergone deep stretching, small black spots and RIDGING may appear on the surface of the extremely deformed areas, thereby affecting the BQ property.