The difference between 304 and 201 stainless steel--popularize scientific knowledge--by CARKIN stainless steel tumbler
There are several families of stainless steels with different physical properties. According to the American Iron and Steel Institute, stainless steel can be numerical numerical and represented such as 200 series, 300 series, 400 series, in which both of 201 and 304 are commonly-used steel which has good corrosion resistant properties, and good machining and polishing performance. As we all know, they can be be regard as substitutes for each other in some applications. So what's the difference?
1. Different chemical composition
Chemical Composition is the the key to study and determinate the physical properties of 201 and 304. We are indicating the chemical composition of the two analyzed SS grades we are studying in the table below.
2. Different price
304 is more expensive than 201 because of the addition of nickel, which also leads to a better corrosion resistance than 201.
3. Different appearance
304 tubes ans sheets offer better bright and not easy to rust. 201 contains more content of high manganese with a dark ligh surface, easy to rust.
4. Different toughness
201 stainless steel material is relatively hard than 304 stainless steel, which is more resilient, fatigue resistance is much better than 201.
5. Different application
201 steel can be used as a substitute material for 304 steel because of its economy. It has magnetic after cold processing and is used in the field of railway vehicle quality or building decoration with less strict requirements. And 304 is the most widely used heat-resistant steel, mainly used in food production equipment, chemical equipment, nuclear energy and so on.
How to differentiate 201 and 304?
1. Spark identification method.The amount, shape, bifurcation and color of sparks generated by the oxidation of various element particles under the grinding conditions of iron and steel with high speed friction and high temperature will be different due to different steel types. This method is used to identify the chemical composition (constituent elements) and approximate content of materials.Use grinding machine with grinding wheel to gently polish 201 and 304 stainless steel, 201 spark longer, thicker, more, and the tail fork, while 304 stainless steel spark shorter, thin, less, and the tail fork. Pay attention to grinding to ensure that the test method is consistent to facilitate the distinction.
2. Identification of stainless steel test solution. Also known as stainless steel pickling potion, this potion and stainless steel surface chemical reaction and produce different colors, can clearly determine the stainless steel stainless steel plating model. Apply stainless steel pickling cream to 201 and 304 kinds of stainless steel tubes respectively and observe the color change of the steel tubes after 2 minutes. The color red is 201 material and light green or colorless is 304 material.
