201 Stainless steel, 201 Seamless stainless steel pipe

What is 201 seamless stainless steel pipe?

201 stainless steel is an austenitic stainless steel whose chemical composition mainly includes C, Cr, Ni, Mn, Si, P, S and other elements. Its characteristics mainly include good acid and alkali resistance, good welding performance and processability, high density, no bubbles in polishing, no pinholes, etc. This material of stainless steel is mainly used to produce various watch cases, watch strap bottom covers, etc. It is also suitable for decorative tubes, industrial tubes and some shallow stretched products. "Seamless tubing" refers to the manufacturing process of stainless steel pipes.

201 stainless steel marking method:

201 stainless steel pipe--S20100 (AISI/ASTM)

AISI (American Iron and Steel Institute) uses three digits to represent various standard grades of wrought stainless steel. Among them:

1. Austenitic stainless steel is marked with numbers in the 200 and 300 series.
2. Ferritic and martensitic stainless steels are represented by 400 series numbers.

For example, some of the more common austenitic stainless steels are marked with 201, 304, 316 and 310, ferritic stainless steels are marked with 430 and 446, and martensitic stainless steels are marked with 410, 420 and 440C. Phase (austenitic-ferritic) stainless steels, precipitation hardened stainless steels and high alloys with an iron content of less than 50% usually have patented or trade names.

201 stainless steel is part of the 200 series, indicating that it belongs to the category of austenitic stainless steel. Although the corrosion resistance of 201 stainless steel is weaker than that of the 300 series, its market potential is huge.

Chemical composition of 201 stainless steel:

The chemical composition of 201 stainless steel seamless pipe includes carbon, silicon, manganese, chromium, nitrogen, phosphorus and sulfur. The content of manganese is relatively high, which makes the 201 stainless steel seamless pipe have a certain hardness, but during the deep drawing and deep drawing process may crack. Nonetheless, after polishing, 201 stainless steel seamless pipe will not rust in a short period of time and is as non-magnetic as 304 stainless steel, which makes it widely used in the decorative welded pipe industry.

C: ≤0.15
Si: ≤1.00
Mn: 5.5～7.50
Cr: 16.0～18.0
N: ≤0.25
P: ≤0.060
S: ≤0.030
Ni: 3.5-5.5

Grades of 201 stainless steel:
The strength grades of 201 stainless steel are usually divided into: S201, S202, S203, S204, S205, etc. These grades represent the tensile strength values of stainless steel, which are 201MPa, 202MPa, 203MPa, 204MPa, and 205MPa respectively.

In the field of stainless steel materials in China, there are many types of 200 series stainless steel, mainly including J1, J3, J4 and the common 201 and 202 steel grades. These steel grades were initially widely used, but later 200 series derivatives with more stringent nickel content controls emerged to meet specific needs.

Among them, 201 steel type is known by its standard number 1Cr17Mn6Ni5N, which is characterized by containing a certain proportion of chromium, manganese and nickel elements. However, with the development of technology, some steel mills in China have further developed special models such as 201C on this basis. The characteristic of 201C is that it appropriately increases the manganese content while reducing the nickel content, which gives it unique advantages in some specific industrial applications.

Production process:
a. Round steel preparation; b. Heating; c. Hot rolling and perforation; d. Cut off the head; e. Pickling; f. grinding; g. Lubrication; h. Cold rolling processing; i. Skim; j. Solid solution heat treatment; k. Straightening; l. Cut the tube; m. Pickling; n. Finished product inspection.

201 stainless steel vs 304 stainless steel:

Compared with 304 stainless steel, the price of 201 seamless stainless steel pipe is usually lower because of its lower nickel content and relatively poor corrosion resistance. However, 201 stainless steel seamless pipes may rust when used for a long time in humid and salty air. Nevertheless, there is also a stainless steel detection solution on the market that can distinguish the type of stainless steel in a few seconds through a simple chemical reaction. This method is convenient, accurate and feasible‌.

In general, 201 stainless steel seamless pipe is an economical and practical choice in specific application scenarios due to its low cost and certain corrosion resistance. Although it is not as corrosion-resistant as 304 stainless steel, 201 stainless steel seamless pipe is a viable alternative in certain applications where extremely high corrosion resistance is not required.

Read more: Carbon steel vs Stainless steel or 304 vs. 316 Stainless Steel