Chemical composition of precipitation hardening stainless steel S51748 0Cr17Ni4Cu4Nb

Chemical Composition of Welding Resistant Stainless Steel S51748 0Cr17Ni4Cu4Nb

Stainless steel S51748 0Cr17Ni4Cu4Nb, also known as SUS347, is a high alloy austenitic stainless steel mainly composed of chromium (17 – 20%), nickel (4 – 7%), copper (4 – 5%), and niobium (4%) but also containing manganese (1%), and silicon (0.1%). The high levels of chromium and nickel give it excellent corrosion resistance and formability while the niobium content improves its strength and temper resistance. The copper content offers superior weldability and is credited to its ability to resist hot cracking. Additionally, S51748 also contains molybdenum and nitrogen for further corrosion resistance.

While mainly used for welded parts, SUS347 has many other advantages. It offers an impressive high working temperature of 800-900°F and ultimate tensile strength of up to 85 ksi. In addition to having high corrosion resistance to harsh environments, the material is also resistant to crevice corrosion and stress corrosion cracking. It can be found in industrial boilers, heat exchangers, and consumer appliances such as refrigerators and dishwashers.

In order to use stainless steel S51748 0Cr17Ni4Cu4Nb, it must be properly treated. It should be annealed between 850-1200°F to reduce hardness and increase ductility. After annealing, a stress relief of 400-600°F is recommended to prevent warping or distortion. If exposed to an environment that retains moisture, an extra step of stabilizing the material should be implemented. It is also advised to remove oils, chemicals, and dirt build up in order to prevent contamination.

Chemical Composition

Element Content (%)

Carbon 0.03

Manganese 1.00

Silicon 0.10

Chromium 17.00 - 20.00

Nickel 4.00 - 7.00

Copper 4.00 - 5.00

Niobium 4.00

Molybdenum 0.50 - 1.00

Nitrogen 0.25

Phosphorus 0.045

Sulfur 0.03

Iron Balance

The precipitation hardened stainless steel S51748 0Cr17Ni4Cu4Nb has several properties which make it an ideal choice for applications requiring enhanced strength and corrosion resistance. The chemical composition of this steel is characterized by the following composition:

C: 0.040%, Mn: 1.00%, P: 0.040%, S: 0.030%, Si: 0.10%, Cr: 17.00%, Ni: 4.00%, Cu: 4.00%, Nb: 0.10%.

This stainless steel has excellent mechanical properties such as high tensile strength and yield strength. Its ultimate tensile strength ranges up to 800MPa and the yield strength up to 630MPa. As the steel is precipitation hardened, its resistance to corrosion is very high. During heat treatments, the features of the steel are further improved with the help of precipitation hardening techniques. These techniques help in retaining the corrosion and mechanical strength of the steel. The steel has a very tough and strong surface which makes it highly resistant to scratches and dents.

Additionally, this stainless steel has a low coefficient of thermal expansion, making it a perfect choice for fabricating components which are required to resist thermal shocks and stress levels. Another property making it an ideal steel for several applications is that it has a good weldability. This makes it possible to use this steel in welding applications, where a high strength and corrosion resistant weld is required.

Due to the combination of excellent physical and mechanical properties, the steel S51748 0Cr17Ni4Cu4Nb is a popular and highly versatile choice for industrial applications such as components and parts used in general engineering, fasteners, oil and gas pipelines, as well as architectural and aerospace components.