Currently, most of the stainless steel water bottles sold in the United States, Canada, Europe, and Japan are made of 304 stainless steel and 201 stainless steel. Here,304 stainless steel is also what we called 18/8 stainless steel. Consumers often write emails asking us, what is the difference between 304 stainless steel and 201 stainless steel? What is the difference impact in health and environmental? We will give a detailed explanation in this article
To answer this question, firstly, we have to understand the nature of stainless steel, as well as how to definite the classification and name of stainless steel materials. Stainless steel is a metal alloy. The invention of stainless steel that not easy to rust is a major break through world metallurgical history. At the beginning of the 20th century from 1907 to 1930 , based on the role of chromium in steel and the role and influence of nickel and other elements, metallurgists successively invented martensitic stainless steel with 12 to 13% Gr and 14 to 16% Gr/0.07. ~0.15%C ferritic stainless steel, German Maurer and Strauss invented austenitic stainless steel containing 1.0%C/15~20%Gr/<20%Ni, and then in 1929 Strauss won the famous 18/8 [18%Gr, 8%Ni] stainless steel patents. So far, there are more than 200 types of stainless steel materials used. They have achieved wide and meaningful different roles in the practical application of metal materials. The overall practical application of stainless steel The value is that it is not easy to rust and corrosion resistance. In the atmosphere and weak corrosive media, where the corrosion rate is less than 0.01mm/a, it is considered “corrosion resistant”, and vice versa. In addition to the core role of corrosion resistance from the perspective of use, acid-resistant stainless steel, heat-resistant (high-temperature) stainless steel, and low-temperature stainless steel have been subsequently developed.
From the above development of stainless steel, we know that stainless steel is a general term for a kind of metal alloy that is not easy to rust, and there are more than 200 kinds of them. In order to distinguish each of them, we have to name them and express them. Anyway, we cannot write them in molecular formulas. Which is very difficult to recognize. Stainless steel grades are one of the main ways of expressing stainless steel. However, due to differences in history, language and culture, the development of metallurgical industry and the application of stainless steel in major countries in the world, the expressing method of stainless steel grades is also different.
The United States, Germany, China, Russia, and Japan have their own methods to name various stainless steels.
The three-digit numbers 201 and 304 which we often say are actually the American representation method1: AISI standard steel number representation method, the first digit indicates the type of steel, the other two digits indicate the serial number, 2**: chromium manganese nickel Nitrogen austenitic steel; 3**: nickel-chromium austenitic steel, ** is the omitted serial number, such as 202 and 301 specific numbers are omitted here; in addition, 2: SEA standard uses 5 digits to represent steel No., such as 30408, 30403, 60316, etc., 3: ACI standard steel number representation method (omitted), 4: UNS system steel number representation method (omitted).
Here, we briefly mentioned the Japanese stainless steel grade representation method which we often be asked. The Japanese standard is basically referring to AISI of the United States, but adding the prefix “SUS” means stainless steel, and adding “SUH” means heat-resistant steel, such as SUS304. means stainless steel 304.
Well, believing you have already understood the origin of the name [brand] of stainless steel through above explanation .This is very important for everyone to understand all kinds of stainless steel. Knowing the ins and outs, we can better understand various stainless steels and the characteristics of various stainless steels. The difference is simpler and logical and systematic. In fact, we can easily find various common stainless steel entries by Google in which the properties and uses of different grades of stainless steel are described in detail. You can take time to learn and compare the characteristics of various stainless steels if you are interested
304 stainless steel [0Gr18Ni9] and 201 stainless steel [1Cr17Mn6Ni5N]are two stainless steel materials named according to the American AISI standard, and are also widely used in many industries around the world. It should be noted that stainless steel is difficult to just looking at it. It is inevitable to make mistakes that even very experienced practitioners can tell the difference through visual observation. 304 and 201 are two austenitic stainless steel, solid solution treated 304 stainless steel, 201 stainless steel are non-magnetic, and the magnetic is due to the internal structure damage caused by cold working or the formation of a small amount of ferrite structure; 304 is a stainless steel type The most famous and most widely used type of stainless steel is the 8 nickel 18 chromium stainless steel that we often say. From the perspective of application, 304 is the most common, cost-effective, and most versatile stainless steel material. The quantity and scope of application are ranked first in the world.
Physical properties of 304 stainless steel:
Tensile strength σb (MPa)≥520
Conditional yield strength σ0.2 (MPa)≥205,
Section shrinkage ψ (%)≥60,
Elongation rate δ5 (%)≥40,
Hardness: ≤ 187HBW;≤90HRB;≤200HV,
Density (20℃, g/cm3): 7.93,
Delting point (℃): 1398~1454,
Specific heat capacity (0~100℃, KJ·kg-1K-1): 0.50,
Thermal conductivity (W·m-1·K-1): (100°C) 16.3, (500°C) 21.5,
Linear expansion coefficient (10-6·K-1): (0~100°C) 17.2, (0~500°C ) 18.4,
Resistivity (20℃, 10-6Ω·m): 0.73,
Longitudinal modulus of elasticity (20℃, KN/mm2): 193;
The following table uses JIS G4305 (cold-rolled stainless steel plate, sheet and strip) to view its element ratio.
The content of nickel, manganese and other elements is very different. This results in obvious differences in the smelting, cost, performance, and use of the two materials. 304 stainless steel is a representative of stainless steel. All aspects of performance have a relatively perfect balance. As the most widely used stainless steel material, it has good processing performance, welding, cold forming, and excellent corrosion resistance. It has become the first choice in many fields; However,201 stainless steel material saves nickel which greatly reduce the cost of materials directly .Nickel metal is the main component of the cost of stainless steel materials, accounting for about 75% of 304 stainless steel materials], which also brings a strong competitive advantage to 201 stainless steel, and does not require corrosion resistance. In the case of high, it is replaceable. Compared with 304 stainless steel, although its corrosion resistance and cold working performance are obviously reduced, the hardness increases, the pull-up rate is reduced, and the turning performance is slightly worse, some materials in 201 stainless steel also achieve certain excellent performance, such as adding a certain amount of copper. Improved softness, excellent processing toughness, so that 201 stainless steel material has been rapidly developed and widely used.
Here, we briefly talked about the difference between 201 and 304 which is very different.
1. Corrosion resistance: The difference between 201 stainless steel and 304 stainless steel is obvious. In the daily neutral, 201 is also possible be corrosion- resistant in daily clean, dry and pollution-free environment. The common anti-theft nets in inland areas are mostly 201 stainless steel pipes. 304 stainless steel is a very good material for use in the field of architectural decoration. Generally, it can be competent and does not require special maintenance for decades.
2. Processing performance, as shown in the above and the icon, 201 stainless steel has higher hardness, lower elongation rate than 304 stainless steel, and less ductility which We also say that it is harder and more brittle. The cold working performance of 304 stainless steel is better than 201 stainless steel. Therefore, it is easier to process and weld 304 stainless steel in most cases such as processing sheet metal, profile turning, pipe bending and expansion cones, etc. 201 stainless steel is worse, but it does not mean that it is much worse. The specific conditions cannot be covered here.
3. Price: 201 stainless steel uses about one-third of the market while 304 stainless steel is about one-third to one-half the price of 304 stainless steel is 1.6 times the price of 201 stainless steel. The price and cost advantage of 201 stainless steel is obvious.
4. Serviceable range: low-end products and daily necessities, many of which are made of 201 stainless steel, such as kitchen utensils, shoe racks, and even tableware in the wholesale market, low-end furniture tables and chairs, etc., door and window security nets, especially inland area and architectural decoration guardrails, etc. There is also some mechanical hardware, which is more difficult to judge. It should be pointed out that 201 stainless steel is a very wide range of materials and we cannot comprehensively summarize it; However, for authentic food sanitation, the material used for medical devices is 304 or higher quality 316L stainless steel. 304 is very common. Most of the good quality products or water bottle and kitchen utensils in the kitchen should be 304 stainless steel. High-end furniture and household products are also the most common made in 304 stainless steel.