F44、X1NiCrMoCu25-18-7、00Cr20Ni18Mo6CuN

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

F44 (254SMO, S31254, 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. F44 also has good resistance to uniform corrosion. 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, the more famous is F44 containing 6% Mo. This type of steel has very good local corrosion resistance. It has good pitting resistance (PI≥40) and 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 F44 (254SMO, S31254, 1.4547) is a high-alloy material, it is quite complicated in the manufacturing process. Generally, people can only rely on traditional processes to manufacture this special stainless steel, such as pouring, forging, and calendering. It is also possible to make seamless steel pipes by center drilling, cold rolling or cold drawing.

 

Chemical composition of F44 (254SMO, S31254, 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

 

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

Density: 8.24g / cm3,

Melting point: 1320-1390 ℃,

Magnetic: None

 

Mechanical properties of F44 (254SMO, S31254, 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)

 

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

F44 (254SMO, S31254, 1.4547) stainless steel is a high corrosion-resistant super austenitic stainless steel. It is developed for halide and acid environments and is widely used in harsh working environments such as high-concentration chloride ion media and seawater. In various industrial applications of acidic media, especially in halide-containing acids, 254SMO is far superior to other stainless steels, and in some cases 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, excellent resistance to intergranular corrosion, and is a cost-effective stainless steel. widely used.

 

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

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

 

F44 (254SMO, S31254, 1.4547) Application fields of super austenitic stainless steel:

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

1. A large number of field experiments and extensive experience have shown that F44 has high crevice corrosion resistance in seawater even at slightly higher temperatures, and only a few types of stainless steel have this performance.

2. The corrosion resistance of F44 in acid 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 F44 has a high nitrogen content, its mechanical strength is higher than other types of austenitic stainless steel. In addition, F44 also has high ductility and impact strength and good weldability.

4, F44's high molybdenum content can make it have a higher oxidation rate during annealing, so that after pickling, it has a rougher surface than ordinary stainless steel. However, this has no adverse effect on the corrosion resistance of the steel.