Main elements of SUS 316L stainless steel

Carbon (C): The content does not exceed 0.03%, which helps prevent intergranular corrosion and embrittlement of stainless steel at high temperatures.Silicon (Si

Carbon (C): The content does not exceed 0.03%, which helps prevent intergranular corrosion and embrittlement of stainless steel at high temperatures.

Silicon (Si): The content generally does not exceed 1.00%. Silicon is mainly used as a deoxidizer in stainless steel and has little effect on the corrosion resistance of stainless steel.

Manganese (Mn): The content usually does not exceed 2.00%. Manganese can improve the strength and toughness of stainless steel, but too high a manganese content may reduce its corrosion resistance.

Phosphorus (P): The content usually does not exceed 0.045% (some data give no more than 0.040%). Phosphorus mainly exists as an impurity in stainless steel and has a certain effect on corrosion resistance.

Sulfur (S): The content generally does not exceed 0.03%. Sulfur is also an impurity element in stainless steel, which is not conducive to corrosion resistance.

Chromium (Cr): The content is between 16.00% and 18.00%. Chromium is the main element that forms the corrosion resistance of stainless steel. It can form a dense oxide film on the surface of steel to prevent further oxidation of steel.
Nickel (Ni): The content is between 12.00% and 15.00% (some materials give 10-14%). Nickel can improve the corrosion resistance and toughness of stainless steel, and also help to form austenite structure.
Molybdenum (Mo): The content is between 2.00% and 3.00%. The addition of molybdenum can significantly improve the corrosion resistance of stainless steel to chloride ions, making it perform well in marine environments and some chemical media.

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.