SUS 201 Composition

SUS 201 is an austenitic stainless steel, and its chemical composition mainly includes chromium (Cr), nickel (Ni), manganese (Mn), carbon (C), silicon (Si), and

SUS 201 is an austenitic stainless steel, and its chemical composition mainly includes chromium (Cr), nickel (Ni), manganese (Mn), carbon (C), silicon (Si), and a small amount of phosphorus (P) and sulfur (S). The following is a detailed summary and representation of the composition of SUS 201:

Main components
Chromium (Cr):
Content range: According to information from multiple sources, the chromium content in SUS 201 is usually between 15.0%-18.0%, and some sources indicate that its content can reach 17%-19%. Chromium is one of the most important alloying elements in stainless steel, which gives stainless steel high strength and excellent corrosion resistance.
Nickel (Ni):
Content range: The nickel content of SUS 201 is relatively low, and the range given by different sources varies. Some sources indicate that its nickel content is 1.25%-2.50%, while others show that its nickel content is between 3.5%-5.5% or 4%-6%. The lower nickel content makes SUS 201 a low-cost stainless steel, also known as low-nickel stainless steel.
Manganese (Mn):
Content range: SUS 201 contains a certain amount of manganese to improve its mechanical properties and processing properties. The manganese content is usually between ≤1.0% and 5.5%-7.5%, depending on different production standards and process requirements.
Other components
Carbon (C):
Content range: The carbon content in SUS 201 is low, usually between 0.12%-0.20%, and some data indicate that its carbon content is below 0.15%. Low carbon content helps improve the welding performance and corrosion resistance of stainless steel.
Silicon (Si):
Content limit: The silicon content is usually limited to ≤1.0% to ensure that the mechanical properties and corrosion resistance of stainless steel are not affected.
Phosphorus (P) and sulfur (S):
Content limit: As impurity elements, phosphorus and sulfur are also strictly limited to very low levels, usually phosphorus (P) ≤0.04%, sulfur (S) ≤0.03%. These restrictions help reduce defects such as inclusions and cracks in stainless steel, improving its overall performance.

stainless steel processing

The manufacture of stainless steel involves a series of processes. First, the steel is melted, and then it is cast into solid form. After various forming steps, the steel is heat treated and then cleaned and polished to give it the desired finish. Next, it is packaged and sent to manufacturers, who weld and join the steel to produce the desired shapes.

The raw materials that constitute a stainless steel item are placed together and melted in a giant electric furnace. Intense heat is applied rigorously for a period of 8 to 12 hours during this step. Once the melting is complete, the molten steel is cast into desired semi-finished forms. Some of the most common forms or shapes include slabs, blooms (rectangular shapes), billets (these could either be round or square), rods, and tube rounds.

In the second stage, the semi-finished steel shapes undergo a series of forming operations. For instance, the stainless steel is hot rolled (heated and passed through enormous rolls). The blooms and billets mentioned above are converted to bar and wire. The slabs on the other hand are formed into plates, strips or sheets. It is very common to turn semi-finished steel shapes into bars, as it is the most versatile stainless steel form (it comes in all grades and sizes). You have round, square, octagonal, and hexagonal bars, each suitable for a different type of application.

The various stainless steel forms undergo a thorough annealing process during this step. Annealing is another name for heat treatment where the stainless steel is heated and cooled in a controlled environment. The purpose of this heat treatment is to relieve the pent-up stress inside the stainless steel and soften the material to make it more suitable for a wide variety of applications. The people in charge of carrying out the annealing process have to be very careful about the conditions as even the slightest of changes in the temperature, pressure, duration, or cooling rate could result in a faulty product.

During the annealing process, a certain amount of scale appears on the surface of the stainless steel. This scale can be removed using a number of different processes that are collectively known as descaling. Pickling is one of the more common methods of carrying out the descaling process.

The semi-finished, heat-treated, and descaled stainless steel forms are cut into specific shapes in this step. Mechanical cutting is performed with the aid of guillotine knives, blanking, nibbling, and high-speed blades.

Finishing is applied to help the stainless steel product achieve its signature aesthetically appealing appearance. Finishes are also needed to make the stainless steel product smooth and easier to clean, which is a top requirement in sanitary applications.