Stainless steel is an essential material used in various industries, from construction to food processing. However, not all stainless steel is created equal.
There are significant differences between stainless steel 201 and 304, and it is crucial to know how to distinguish between the two.
In this article, we will explore the differences between the two types of stainless steel and provide methods for identifying them. We will also discuss the chemical composition and various techniques for distinguishing between them, including dropping liquid medicine, grinding spark status, and spectrometer detection.
Additionally, we will answer the question of which is better between 304 and 201 stainless steel, and provide insights into the procurement risks associated with these materials.
By the end of this article, you will have a comprehensive understanding of the differences between stainless steel 201 and 304, and be equipped with the knowledge to make informed decisions when purchasing stainless steel products.
So, grab a cup of coffee and get ready to dive into the world of stainless steel!
1. Differences between stainless steel 201 and 304
How to distinguish 201 and 304 stainless steels?
This article will aid you in identifying the differences and methods of differentiation between stainless steel 304 and 201.
Differences and resolution methods between 201 and 304 stainless steels
|1||Nickel content (Ni)||<2%||8-10.5%|
|2||Price||About 7 yuan/kg||About 14 yuan/kg|
|3||Liquid medicine reaction||Low Ni measuring solution (201), electrified and oxidized for 2-5s, showing rose red||Ni8 measuring solution (304), which lasts for 5-8 seconds after being electrified and oxidized, is red, that is, 304 or the material with more than 8% nickel content|
|4||Grinding spark status||Sparks are relatively scattered||Continuous long spark|
|5||Color sense||Compared with 304201 cold-rolled stainless steel plate, the surface is white||Compared with 201304 cold-rolled stainless steel plate, it is gray (the actual observation is not obvious, but the difference can still be seen)|
|6||Surface tactility||Compared with 304,201 cold-rolled stainless steel plate, the surface is more slippery; Slightly fold a corner of 201 cold-rolled stainless steel plate. After release, it will basically remain in its original state. If it is 304, it will have relatively obvious bending deformation|
- It is important to keep in mind that 304 stainless steel should not be purchased at the market price for 201 stainless steel.
- It is recommended to choose reputable companies for procurement. The credibility of a supplier can be evaluated not only through their verbal commitments, but also through their actions.
2. Chemical composition difference between 201 and 304
The following is a comprehensive analysis of the differences and methods of identification between 201 and 304 stainless steels.
First, let’s examine the chemical composition of 201 and 304 stainless steels:
In order to preserve its inherent resistance to corrosion, 304 stainless steel must contain a minimum of 18% chromium (Cr) and 8% nickel (Ni).
201 stainless steel belongs to the 200 series of stainless steel, which was utilized as an alternative to 300 series stainless steel during World War II.
Compared to 304 stainless steel, 201 stainless steel has a significantly lower nickel content and is therefore less expensive.
201 stainless steel is primarily used for decorative tubes, industrial tubes, and some shallow drawn products. At present, there is no corresponding national standard for 201 stainless steel.
The brand name for 201 stainless steel is 1Cr17Mn6Ni5N, and production standards for 201 stainless steel can vary among manufacturers.
It is important to note that nickel enhances the toughness, heat resistance, and corrosion resistance of stainless steel.
3. How to quickly distinguish 304 and 201 stainless steel?
1. Judgment of dropping liquid medicine
When buying stainless steel, it is essential to determine the type of stainless steel material.
There are several methods for distinguishing between 304 and 201 stainless steels. The most common method is to drop a chemical reagent onto the surface of the stainless steel and observe the color change to determine if it is 304 or 201.
While this method is convenient, it may not always be applicable.
2. Judgment of grinding spark status
Another method is to polish the stainless steel material and identify it as 304 or 201 based on the shape of the sparks produced. This is a commonly used inspection method for scrap recycling personnel.
304 stainless steel produces long sparks, while 201 stainless steel produces relatively dispersed sparks.
3. Tested by the authority
If a definitive quality inspection report is required, it is necessary to seek the services of a third-party organization for chemical composition analysis. This method takes the longest time and incurs the highest cost, but is the only method recognized by the court in the case of a dispute.
4. Spectrometer detection
Another option is the spectrometer detection method, which is a relatively scientific, simple, direct, and widely used method for companies that make large-scale purchases of materials.
The spectrometer instantly reads the elemental content of the stainless steel, allowing for the determination of whether the material is 304 or 201. The reliability and credibility of this method is comparable to that of the chemical analysis method performed by a third-party national testing center.
5. Judge whether there is magnetism
In everyday use, we can also use the magnetic adhesion method to determine the material. 201 stainless steel is magnetic, while 304 stainless steel is typically non-magnetic.
However, some 304 stainless steels may exhibit magnetic properties due to differences in production processes. Therefore, relying solely on the presence or absence of magnetism is not a recommended method for distinguishing between 201 and 304 stainless steels.
6. Judge by unit price and supplier reputation
Distinguishing 304 and 201 stainless steel by visual inspection alone can be challenging.
When buying stainless steel, one suggestion is to first consider the price (per unit) as a factor in determining if it is 201 or 304. Typically, 304 stainless steel is about twice as expensive as 201 stainless steel.
Additionally, it is advisable to choose reputable merchants.
By following these steps, it is possible to avoid purchasing substandard stainless steel products.
4. Which is better, 304 or 201 stainless steel?
- The unit price of 201 stainless steel is lower, making it a more cost-effective option. When the requirements for toughness and corrosion resistance are not demanding, 201 stainless steel is a suitable choice.
- 304 stainless steel has a broader range of applications and offers higher overall cost-effectiveness. It is the preferred option when there are specific requirements for toughness, strength, corrosion resistance, and durability.
- 304 stainless steel can be used as food-grade material, while 201 stainless steel is not recommended for use in food-grade applications. If considerations for later maintenance and corrosion resistance are not a priority, 201 stainless steel can be used for structural parts, decoration, and as inner and outer liner materials for non-food contact containers, among other applications.
It is generally not recommended to use 201 stainless steel for insulation cups, kettles, etc. However, low-cost products made of 201 stainless steel, such as insulation cups and kettles, are widely available in various small shops, online stores, and even shopping malls and supermarkets.
When purchasing stainless steel products, it is important to consider factors such as the material, the reputation of the manufacturer, brand awareness, and other relevant factors to avoid buying counterfeit, low-quality, or potentially harmful products.
5. Procurement risk of 201 and 304 stainless steel
A comprehensive understanding of the differences between 201 and 304 stainless steel can help minimize procurement risks.
Currently, some businesses may misrepresent 201 stainless steel as 304 in their transactions, which is not only unethical and illegal but also poses significant risks to the safety of projects and equipment.
Each grade of stainless steel has unique characteristics, appropriate usage scenarios, and environmental limitations.
By now, you should have a good understanding of how to identify 304 or 201 stainless steel.
Once more, it is crucial to be cautious and consider all factors rather than being swayed by superficial prices.