Why do some bimetallic thermometer is very cheap?1

In the eyes of many consumers, 304 stainless steel and 201 stainless steel is almost no difference, can hardly distinguish with the naked eye, with the two different material qualitative make it after the bimetallic thermometer, price difference is very big, wood Yao instrument has been SS304 material bimetallic thermometer, here to introduce you to some of the ways to distinguish between 304 and 201. 1, specifications: commonly used stainless steel plate is divided into two kinds of models 201 and 304, the actual is different components, 304 quality is better, but the price is expensive, 201. 304 for imports of stainless steel plate, 201 for the domestic stainless steel plate. Up to 17 cr - 2, 201 4. 5 ni - 6 mn - N, Ni is section steel, 301 steel instead of steel. After cold working with magnetic, used in railway vehicles. 3, up to 18 cr - 304 9 ni, is the most widely used of stainless steel, heat-resistant steel. Used in food production equipment, wast, general chemical equipment, nuclear power, etc. Manganese content in the 4, 201 is higher, the surface is very bright with dark light, with high manganese is easy to rust. 304 containing chromium is more, surface is matte, not rust. Both together are compared. The corrosion resistance of the most important thing is different, the corrosion resistance of 201 is very poor, so the price will be much cheaper. Because 201 nickel is low, so the price is lower than that of the 304, and corrosion resistant performance is better than 304. The difference between 5, 201 and 304 is the problem of nickel. And 304 prices are more expensive, but 304, at least you can guarantee in use process will not rust. 6, stainless steel is not easy to rust because forming a rich chromium oxide in the surface of steel body can protect the steel body, 201 materials belong to high manganese steel is 304 high hardness, high carbon low nickel. 7, the different components ( Mainly from the carbon, manganese, nickel, chromium aspects to distinguish between 201 and 304 stainless steel) Steel grade carbon ( C) Silicon ( Si) Manganese ( Mn) Phosphorus ( P) Sulfur ( S) Chromium ( Cr) Nickel ( Ni) Molybdenum ( Mo) Copper ( Cu) AISI( 304). ≤0. 08 ≤1. 00 ≤2. 00 ≤0. 045 ≤0. The 18 - 20 8 - 10AISI( 201). ≤0. 15 ≤1. 5 00. 5 - 7. 5 ≤0. 05 ≤0. The 16 - March 18. 5 - 5. 5 what has been discussed above, the stainless steel 201 bimetallic thermometer is easy to rust, corrosion resistance is poor; And 304 stainless steel bimetallic thermometer is not easy to rust, corrosion resistance is better.