Briefly describe the basic knowledge and purchase method of stainless steel
1. Basic knowledge of stainless steel
The main component of stainless steel is low carbon alloy steel containing nickel and chromium, which is divided into nickel series stainless steel and chromium series stainless steel according to the proportion of nickel and chromium. Stainless steel is divided into austenite, martensite, ferrite and precipitation hardening stainless steel according to its structure. The high-quality stainless steel materials on the market should have a chromium content of not less than 18% and a nickel content of not less than 10%. At present, stainless steel sinks are made of stainless steel hot-rolled thick plates (thin plates with thickness less than 3mm are thin plates, and thick plates with thickness greater than 3mm are thick plates).
Second, the production process
1. Raw materials
At present, the common raw materials of domestic stainless steel sink manufacturers are 0.8-1.0MM thick plates, and the commonly used model is Japan (JIS) SUS304, which corresponds to China (GB) 0Cr18Ni9 (0Cr19Ni9). Too thin plates will affect the service life and strength of the sink, and too thick plates will easily damage the washed dishes.
2. Process
There are 2 processes in the production of stainless steel sinks
One is the welding method. The groove surface and the groove body are punched respectively, and the two are connected by welding method, and the surface of the weld is filled and polished. Generally, no welding marks can be seen on the front appearance. This production method has a simple process and only requires small stamping equipment and simple molds. Generally, stainless steel plates of about 0.5-0.7MM are used, and the production process is less lossy and the cost is relatively low.
The other is the one-shot molding method. The water tank is pressed from a whole sheet of material, which requires high processing equipment and molds. Due to the high requirements on the quality and ductility of the sheet for one-time molding, 0.8-1MM thick plate is generally used for stamping, and the overall Dies, imported stamping equipment. Due to the large cutting loss of the edge of the plate in the production of the one-shot molding method, and the investment of molds and equipment, the cost is high.
3. Surface treatment
The surface treatment of the sink is mainly matte, with brushed, frosted, etc., so that even if it is old, the scratches on it cannot be seen.
3. How to choose a stainless steel sink
As an ordinary consumer, how to identify stainless steel sinks? Of course, the price is the main reference factor, but it is not entirely the case. There are too many things of inferior quality and high price. In the face of stainless steel sinks that cost more than 1,000 yuan at every turn, consumers are often helpless and can only follow the trend to buy or be misled by JS. The following combines personal experience to introduce several soil methods for selecting stainless steel sinks.
1. Specific thickness: As mentioned above, good stainless steel sinks use thicker plates. Because the edge of the sink is processed, it is difficult to see the thickness at once. The easiest way is to press the surface of the sink slightly. Going down, it means that the material is very thin (hehe, it is recommended to buy a car on the Internet to check the thickness of the steel plate), of course, if you can borrow a vernier caliper and a spiral micrometer, it will not be so troublesome.
2. Weight: Stainless steel is an iron alloy. The specific gravity of steel is 7.87, and heavy metals such as nickel and chromium are added to it. The specific gravity of these metals is larger than that of steel, so the weight is relatively heavy (of course, the thickness of the plate should also be referred to). If it is counterfeit, inferior stainless steel, such as chrome-plated steel, the weight is light.
3. Look at the process: there are welding method and integral molding method. We have seen some name brand sinks with the same exterior size but with very different prices. There are material factors and process costs. Of course, it can be said with certainty that the stainless steel sink material of the one-piece molding method is definitely better than the welding method. First-class sinks are generally produced by one-time stamping method, but the price is relatively high! Of course, there are also low-end products in famous brands. There are many welding methods. You can know it by touching it with your hand.
4. Scraping the surface: Now JS is rampant, and the traps are dense. Some stainless steels are actually a layer of steel plated with a layer of chrome, and the price is not necessarily cheap. This is a bad move and should be used only when it is safe to do so. If we like a sink, but have doubts about its material, we can lift the sink sample from the counter while the store is crowded and swipe it with the key (be careful not to On the inside of the water tank, don't scratch the coating and sound insulation pad at the bottom, it is useless), and then what is the condition of the scratched part, if there is no scratch, it means that the material is ok.
