1. Differences between 201 and 304 stainless steel
How to distinguish 201 and 304 stainless steels?
This article will help you identify the differences and differentiation methods between 304 and 201 stainless steel.
Differences and resolution methods between 201 and 304 stainless steels
| No. | Contrast item | 201 | 304 |
| 1 | Nickel (Ni) content | <2% | 8-10.5% |
| two | Price | About 7 yuan/kg | About 14 yuan/kg |
| 3 | Liquid medicine reaction | Low Ni(201) measuring solution, electrified and oxidized for 2-5s, showing pink red | Ni8 (304) measuring solution, which lasts 5 to 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 dispersed | 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 touch | Compared with cold-rolled 304,201 stainless steel plate, the surface is more slippery; Slightly bend one corner of the cold-rolled 201 stainless steel plate. After launch, it will basically remain in its original state. If it is 304, it will have relatively obvious bending deformation | |
Reminder:
- It is important to keep in mind that 304 stainless steel should not be purchased at the market price of 201 stainless steel.
- It is recommended to choose reputable companies for purchases. A supplier's credibility can be assessed not only through their verbal commitments, but also through their actions.
2. Difference in chemical composition between 201 and 304
The following is a comprehensive analysis of the differences and identification methods between 201 and 304 stainless steels.
First, let's look at the chemical composition of 201 and 304 stainless steels:
304 stainless steel is a type of stainless steel material manufactured in accordance with American ASTM standards. It is commonly referred to as the national standard 06Cr19Ni10.
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 used 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 cheaper.
201 stainless steel is mainly used for decorative tubes, industrial tubes and some shallow drawn products. Currently, there is no corresponding national standard for 201 stainless steel.
The hallmark of 201 stainless steel is 1Cr17Mn6Ni5N, and 201 stainless steel production standards can vary between manufacturers.
It is important to note that nickel increases 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 purchasing stainless steel, it is critical to determine the type of stainless steel material.
There are several methods to distinguish between 304 and 201 stainless steels. The most common method is to place a chemical reagent on the surface of the stainless steel and observe the color change to determine whether it is 304 or 201.
Although 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 an inspection method commonly used by scrap metal recycling personnel.
304 stainless steel produces long sparks, while 201 stainless steel produces relatively dispersed sparks.
3. Tested by 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 most time and incurs the highest cost, but it is the only method recognized by the court in the event of a dispute.
4. Spectrometer detection
Another option is the spectrometer detection method, which is a relatively scientific, simple, direct method and widely used by companies that make large-scale material purchases.
The spectrometer instantly reads the elemental content of stainless steel, allowing you to determine 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 daily 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 purchasing stainless steel, one suggestion is to first consider price (per unit) as a factor in determining whether it is 201 or 304. Typically, 304 stainless steel is about twice as expensive as 201 stainless steel.
Furthermore, it is advisable to choose reputable traders.
By following these steps, you can avoid purchasing inferior quality 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 economical option. When toughness and corrosion resistance requirements are not demanding, 201 stainless steel is a suitable choice.
- 304 stainless steel has a wider range of applications and offers greater overall value for money. It is the preferred option when there are specific requirements for toughness, strength, corrosion resistance and durability.
- 304 stainless steel can be used as a food grade material, while 201 stainless steel is not recommended for use in food grade applications. If considerations for aftercare and corrosion resistance are not a priority, 201 stainless steel can be used for structural parts, decoration, and as internal and external lining materials for non-food contact containers, among other applications.
It is generally not recommended to use 201 stainless steel for insulated cups, kettles, etc. However, low-cost products made from 201 stainless steel, such as insulated cups and kettles, are widely available in various small stores, online stores, and even shopping malls and supermarkets.
When purchasing stainless steel products, it is important to consider factors such as the material, the manufacturer's reputation, brand recognition and other relevant factors to avoid purchasing counterfeit, low quality or potentially harmful products.
5. Risk of purchasing 201 and 304 stainless steel
A comprehensive understanding of the differences between 201 and 304 stainless steel can help minimize procurement risks.
Currently, some companies 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 type 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 again, it is crucial to be cautious and consider all factors, rather than being influenced by superficial prices.
6. Is 201 stainless steel food grade?
Although 201 stainless steel is often used in kitchenware due to its affordable price, it is not considered food grade. This is because it can contain higher levels of manganese and nitrogen, which can potentially contaminate food, impacting its safety. For food-related applications, 304 or 316 stainless steel, known as food-grade stainless steel, is generally recommended for its superior corrosion resistance.
