S31254 Super Austenitic Stainless Steel W.Nr1.4547

S31254 (F44, 254SMO, 1.4547) Super austenitic stainless steel overview:

S31254 (F44, 254SMO, 1.4547) is a super austenitic stainless steel. Because of its high molybdenum content, it has extremely high resistance to pitting and crevice corrosion. This grade of stainless steel was developed and developed for use in halide-containing environments such as seawater. S31254 also has good uniform corrosion resistance. Especially in halogen-containing acids, this steel is superior to ordinary stainless steel. Its C content is <0.03%, so it is called pure austenitic stainless steel (<0.01% is also called super austenitic stainless steel).

Super stainless steel is a kind of special stainless steel. It is different from ordinary stainless steel in chemical composition at first. It refers to a high alloy stainless steel containing high nickel, high chromium and high molybdenum. Among them, S31254 containing 6% Mo is very famous. This kind of steel has very good local corrosion resistance. It has good pitting resistance (PI≥40) under seawater, aeration, gaps, and low-speed erosion conditions. Good stress corrosion resistance, it is a substitute for Ni-based alloys and titanium alloys. Secondly, in terms of high temperature or corrosion resistance, 304 stainless steel is irreplaceable. In addition, from the classification of stainless steel, the metallographic structure of special stainless steel is a stable austenitic metallographic structure.

Because the special stainless steel S31254 is a high-alloy material, its manufacturing process is Yquite complicated. Generally, people can only rely on traditional processes to manufacture this special stainless steel, such as pouring, forging, rolling, and can also punch through the center. Cold rolled or cold drawn to make seamless steel pipes.

 

Chemical composition of S31254 (F44, 254SMO, 1.4547) super austenitic stainless steel:

C≤	Si≤	Mn≤	P≤	S≤	Cr≥	Ni≥	Mo≥	N≤	Cu≤	Fe≤
0.02	0.80	1.00	0.030	0.010	19.5 20.5	17.5 18.5	6.0 6.5	0.18 0.22	0.50 1.00	margin

 

Physical properties of S31254 (F44, 254SMO, 1.4547) super austenitic stainless steel:

Density: 8.24g / cm3,

Melting point: 1320-1390 ℃,

Magnetic: None

 

Mechanical properties of S31254 (F44, 254SMO, 1.4547) super austenitic stainless steel:

1. Mechanical properties: tensile strength: σb≥650Mpa,

2. Yield strength: σb≥310Mpa

3. Elongation: δ≥40%.

4. Hardness: 182-223 (HB)

 

Corrosion resistance of S31254 (F44, 254SMO, 1.4547) super austenitic stainless steel:

S31254 (F44, 254SMO, 1.4547) stainless steel is a high corrosion-resistant super austenitic stainless steel. It is developed for halide and acid environments. It is widely used in harsh working environments such as high-concentration chloride ion media and seawater. S31254 is far superior to other stainless steels in various industrial occasions in acid media, especially in halide-containing acids. In some cases, it can be comparable to Hastelloy and titanium. The low carbon content and high molybdenum content make it have better resistance to pitting and crevice corrosion, and excellent resistance to intergranular corrosion. It is a cost-effective stainless steel. It is used in chemical, desulfurization and environmental protection fields at home and abroad widely used.

 

S31254 (F44, 254SMO, 1.4547) welding materials for super austenitic stainless steel:

Welding wire: ERNiCrMo-3, electrode: ENiCrMo-3.

 

S31254 (F44, 254SMO, 1.4547) Super austenitic stainless steel applications:

1. Ocean: marine structures in the sea environment, seawater desalination, seawater aquaculture, seawater heat exchange, etc.

2. Environmental protection field: flue gas desulfurization equipment for thermal power generation, wastewater treatment, etc.

3. Energy field: atomic power generation, comprehensive utilization of coal, sea tide power generation, etc.

4. Petrochemical industry: oil refining, chemical and chemical equipment, etc.

5. Food field: salt making, soy sauce brewing, etc.

6. High-concentration chloride ion environment: paper industry, various bleaching devices

 

Corrosion resistance of S31254 (F44, 254SMO, 1.4547) super austenitic stainless steel:

1. A large number of field experiments and extensive use experience show that even at slightly higher temperatures, S31254 has high crevice corrosion resistance in seawater, and only a few types of stainless steel have this performance.

2. The corrosion resistance of S31254 in acidic solutions and oxidizing halide solutions such as those required for bleaching in the paper industry can be compared with the nickel-based alloys and titanium alloys with the strongest corrosion resistance.

3. Because S31254 has a higher nitrogen content, its mechanical strength is higher than other types of austenitic stainless steels. In addition, S31254 also has high ductility and impact strength and good weldability.

4. The high molybdenum content of S31254 can make it have a higher oxidation rate during annealing, so that it has a rougher surface than ordinary stainless steel after pickling. However, this has no adverse effect on the corrosion resistance of the steel.