What is X4CrNi18-12?

X4CrNi18-12 is a stainless steel grade also known as 1.4301 stainless steel. It is an austenitic stainless steel with good corrosion resistance, machinability and strength. This kind of steel is usually used in the manufacture of pressure vessels, food processing equipment, chemical equipment, medical equipment, etc.

What is the chemical composition of X4CrNi18-12?

X4CrNi18-12 is an austenitic stainless steel whose chemical composition is as follows:

Chromium (Cr): 18%

Nickel (Ni): 8%

Carbon (C): no more than 0.07%

Silicon (Si): no more than 1.0%

Manganese (Mn): no more than 2.0%

Phosphorus (P): no more than 0.045%

Sulfur (S): no more than 0.015% 

What are the physical properties of X4CrNi18-12?

The physical properties of X4CrNi18-12 stainless steel are as follows:

Density: 7.9 g/cm³

Melting point: 1400-1450°C

Coefficient of thermal expansion: 17.2×10^-6/°C (at 20°C)

Thermal conductivity: 15 W/(m K) (at 100°C)

Magnetic: Somewhat magnetic, but in most cases non-magnetic.

What are the advantages of X4CrNi18-12?

Good corrosion resistance: Due to the high proportion of chromium and nickel elements, X4CrNi18-12 has good corrosion resistance, can resist the erosion of most acidic and alkaline media, and is also very good for oxidizing and reducing environments stability.

Good machinability: X4CrNi18-12 has good plasticity and toughness, and can be processed by various methods, such as cold processing, hot processing, welding, etc.

Good high temperature strength: Due to its high chromium and nickel content, X4CrNi18-12 stainless steel can maintain good strength and corrosion resistance at high temperatures.

Good aesthetics: X4CrNi18-12 stainless steel has a smooth surface, easy to clean, bright color, and is used for making decorations and furniture.

What are the disadvantages of X4CrNi18-12?

Easy to magnetize: Although X4CrNi18-12 is stainless steel, magnetization may still occur under certain conditions, such as strong magnetic field or high temperature.

Not suitable for fluoride-containing media: Fluoride-containing media may cause corrosion and damage to X4CrNi18-12.

Higher price: Due to its excellent performance and wide application, the price of X4CrNi18-12 stainless steel is relatively high, so it may not be suitable in some application scenarios.

Poor Formability: Relative to other steels, X4CrNi18-12 is less malleable and may therefore not be suitable for some demanding machining and forming applications.

What are the uses of X4CrNi18-12?

X4CrNi18-12 stainless steel has the advantages of excellent corrosion resistance, high temperature strength, aesthetics and machinability, so it is widely used in industry and life. Its main uses include:

Chemical industry: X4CrNi18-12 stainless steel can be used to manufacture chemical equipment such as chemical containers, storage tanks, pipelines, pumps, etc. Its good corrosion resistance can resist the erosion of most chemical media, especially in acidic and alkaline environments. better stability.

Food processing and pharmaceutical industry: X4CrNi18-12 stainless steel has good corrosion resistance and hygienic performance, so it is widely used in food processing and pharmaceutical industries, such as manufacturing storage tanks, pipelines, reactors and other equipment.

Aerospace industry: Due to its high-temperature strength and corrosion resistance, X4CrNi18-12 stainless steel can be used to manufacture high-temperature components such as engine components, turbine blades, and gas turbine blades.

Building decoration: X4CrNi18-12 stainless steel has a smooth, beautiful surface and is easy to clean, so it is used to make building decoration materials, such as doors and windows, stair handrails, interior decoration, etc.

Automobile manufacturing: X4CrNi18-12 stainless steel can be used in the manufacture of auto parts, such as exhaust pipes, fuel tanks, intake manifolds, etc.

How is X4CrNi18-12 heat treated?

The heat treatment of X4CrNi18-12 stainless steel mainly includes two steps of solution annealing and quenching.

Solution annealing: carried out in the temperature range of 850°C-1050°C, the purpose is to eliminate the stress and metallographic structure changes in the steel, improve plasticity and processability, and improve the corrosion resistance and heat resistance of the material at the same time. The solution annealing time depends on the thickness and shape of the steel, generally 1-2 hours.

Quenching: The quenching temperature is about 1000°C, the purpose is to increase the hardness and strength of X4CrNi18-12, but it will also reduce its corrosion resistance. During the quenching process, it should be ensured that the surface of the steel is not affected by excessive cooling. Methods such as heating salt baths or insulation materials can be used to make the cooling rate of the steel uniform.

How to weld X4CrNi18-12?

X4CrNi18-12 stainless steel can be joined by a variety of welding methods, including manual arc welding, TIG argon arc welding, MIG gas shielded welding and laser welding.

The following are several common welding methods and precautions:

Manual arc welding: suitable for stainless steel plates and pipes with small thickness. Before welding, both sides of the weld need to be planed and oxides removed. During the welding process, the appropriate arc length and current intensity should be maintained to avoid too much slag splashing and stomata.

TIG argon arc welding: suitable for thinner stainless steel plates and tubes, need to use TIG argon arc welding machine and pure argon for protection. Before welding, it is necessary to clean the surface and remove oxides. During the welding process, the current, voltage and welding speed should be well controlled to ensure the quality of the weld.

MIG gas shielded welding: suitable for larger thickness stainless steel plates and tubes, need to use MIG welding machine and appropriate shielding gas. Before welding, it is necessary to clean the surface and remove oxides. During the welding process, the current, voltage and welding speed should be well controlled to ensure the quality of the weld.

During the welding process of X4CrNi18-12 stainless steel, the following points need to be paid attention to:

Before welding, the surface of the steel should be cleaned to remove pollutants such as oxides and grease.

Appropriate welding materials and shielding gas should be used during welding to prevent excessive oxides and pores.

Control the welding temperature and time well to avoid too much deformation and residual stress.

Adequate cooling and cleaning should be carried out after welding to remove welding slag and pollutants to ensure the quality of the weld and the corrosion resistance of the steel.