304 stainless steel is often used in the inner layer (that is, in direct contact with water) because of its excellent corrosion resistance. 201 stainless steel cannot be used in the inner layer because of its poor corrosion resistance, but can only be used in the outer layer of the heat preservation water tank. However, 201 stainless steel is cheaper than 304 stainless steel, and it is often used by some unscrupulous merchants as 304 stainless steel. The stainless steel water tank made of 201 stainless steel has a very short service life, and it can be corroded by water in about 1-2 years. Hidden danger.
Here's how to identify these two materials in a simple way:
1. The surface of 304 stainless steel and 201 stainless steel used in stainless steel water tanks is usually matte. So we can distinguish it by seeing it with the naked eye and touching it with our hands. 304 stainless steel has a good luster and shine to the naked eye, and it is smooth to the touch; 201 stainless steel is dark in color, lacks luster, and feels rough and not smooth to the touch. In addition, wet your hands with water and touch the stainless steel plates of two different materials respectively. After touching, the water-stained fingerprints on the 304 stainless steel plate are easier to erase, while the 201 stainless steel plate is not easy to erase.
2. Use a grinder to install a grinding wheel to gently grind two stainless steel plates of different materials. When grinding, the sparks of the 201 stainless steel plate are longer, thicker, and more. On the contrary, the sparks of the 304 stainless steel plate are shorter, thinner, and less. When grinding, the strength must be light, and the grinding force should be consistent, so that it is easy to distinguish.
3. Apply stainless steel pickling paste to two stainless steel plates of different materials. After 2 minutes, look at the color change of the stainless steel surface where the paint is applied. If the color is black, it is 201 stainless steel, if it is white or does not change color, it is 304 stainless steel.
