Is there any difference between 904L and 1.4539?

Is there any difference between 904L and 1.4539?

904L super austenitic stainless steel UNS N08904 plate 904L seamless pipe 904L stainless acid-resistant steel with high nickel molybdenum
Inventory of nickel-based alloy materials

904L super stainless steel overview:

904L super austenitic stainless steel is a low-carbon, high-nickel, molybdenum austenitic stainless acid-resistant steel. It is a proprietary material imported from French H·S Company. It has good activation-passivation transition ability, excellent corrosion resistance, good corrosion resistance in non-oxidizing acids such as sulfuric acid, acetic acid, formic acid, and phosphoric acid, and good corrosion resistance in neutral chlorine-containing media. Excellent resistance to pitting corrosion, as well as good resistance to crevice corrosion and stress corrosion. It is suitable for sulfuric acid of various concentrations below 70°C. It can withstand acetic acid of any concentration and temperature under normal pressure and has good corrosion resistance in mixed acids of formic acid and acetic acid.
Super austenitic stainless steel 904L is a high-alloy austenitic stainless steel with low carbon content. It has good corrosion resistance in dilute sulfuric acid and is specially designed for environments with harsh corrosion conditions. It has a high chromium content and sufficient nickel content. The addition of copper makes it highly acid-resistant, especially highly resistant to chloride gap corrosion and stress corrosion cracking. It is not prone to corrosion spots and cracks, and is resistant to spots. Its corrosion resistance is slightly better than other steel types, it has good processability and weldability, and can be used for pressure vessels.
904L super stainless steel grade:

00Cr20Ni25Mo4.5Cu (national standard), UNS N08904 (standard jointly designed by the American Society of Motor Vehicles Engineers and the American Society for Testing and Materials in 1967), DIN1.4539 (German standard), SUS890L, Al-904L,, F904L, NAS 255

904L super stainless steel standard:

ASTM A240/ASME SA-240 (American Society for Testing and Materials standard; the new standard classifies it as a stainless steel series, and the original standard ASME SB-625 classifies it as a nickel-based alloy series), ASTM A276, ASTM A182/ASME SA- 182. ASTM A312/ASMES A312

ASTM B625/ASME B625, ASTM B673/ASME B673

904L super stainless steel physical properties:
Density: 8.24g/cm3

Melting point: 1300-1390 ℃

Tensile strength: σb≥520Mpa

Elongation: δ≥35%

904L super stainless steel metallographic structure: 904L is a completely austenitic structure. Compared with general austenitic stainless steel with high molybdenum content, 904L is not sensitive to the precipitation of ferrite and α phase.

904L super stainless steel processing performance:

Welding performance

Like general stainless steel, 904L can be welded using a variety of welding methods. The most commonly used welding methods are manual arc welding or inert gas shielded welding. The welding rod or wire metal is based on the composition of the base metal and has higher purity, and the molybdenum content is required to be higher than the base metal. Preheating is generally not required before welding, but in cold outdoor operations, in order to avoid condensation of water vapor, the joint part or adjacent area can be heated evenly. Pay attention to the local temperature not exceeding 100°C to avoid carbon accumulation and intergranular corrosion. When welding, small linear energy, continuous and fast welding speed should be used. Generally, heat treatment is not required after welding. If heat treatment is required, it must be heated to 1100~1150℃ and then cooled quickly.

Supporting welding materials and welding processes: ER385 welding wire and E385 welding rod are used for welding 904L

Machining performance

The machining characteristics of 904L are similar to other austenitic stainless steels. There is a tendency for tool sticking and work hardening during processing. Carbide tools with positive rake angles must be used, and vulcanized and chlorinated oils should be used as cutting coolants. The equipment and processes should be based on reducing work hardening. During the cutting process, slow cutting speeds and feed rates should be avoided.

904L corrosion resistance and main use environment:

904L is a kind of austenitic stainless steel with very low carbon content and high alloying designed for environments with harsh corrosive conditions. It has better corrosion resistance than 316L and 317L, while taking into account both price and performance, it is highly cost-effective. . Due to the addition of 1.5% copper, it has excellent corrosion resistance against reducing acids such as sulfuric acid and phosphoric acid. It also has excellent corrosion resistance against stress corrosion, pitting corrosion and crevice corrosion caused by chloride ions, and has good resistance to intergranular corrosion. In pure sulfuric acid in the concentration range of 0-98%, the service temperature of 904L can be as high as 40 degrees Celsius. In pure phosphoric acid in the concentration range of 0-85%, its corrosion resistance is very good. In industrial phosphoric acid produced by wet processes, impurities have a strong impact on corrosion resistance. Among all kinds of phosphoric acid, 904L has better corrosion resistance than ordinary stainless steel. In strongly oxidizing nitric acid, 904L has lower corrosion resistance than highly alloyed steels that do not contain molybdenum. In hydrochloric acid, the use of 904L is limited to lower concentrations of 1-2%. within this concentration range. The corrosion resistance of 904L is better than that of conventional stainless steel. 904L steel has high resistance to pitting corrosion. Its resistance to crevice corrosion in chloride solutions. The force is also very good. The high nickel content of 904L reduces the corrosion rate in pits and crevices. Ordinary austenitic stainless steel may be sensitive to stress corrosion in a chloride-rich environment at temperatures above 60 degrees Celsius. This sensitivity can be reduced by increasing the nickel content of the stainless steel. Due to its high nickel content, 904L has high resistance to stress corrosion cracking in chloride solutions, concentrated hydroxide solutions and hydrogen sulfide-rich environments.

904L application fields:

Petroleum and petrochemical equipment, such as reactors in petrochemical equipment, sulfuric acid storage and transportation equipment, such as heat exchangers, etc., power plant flue gas desulfurization equipment, the main parts used are: the tower body, flue, and door plate of the absorption tower , internal parts, spray systems, etc., scrubbers and fans in organic acid treatment systems, seawater treatment devices, seawater heat exchangers, paper industry equipment, sulfuric acid, nitric acid equipment, acid production, pharmaceutical industry and other chemical equipment, pressure vessels , Food equipment, pharmaceutical factories: centrifuges, reactors, etc., plant food: soy sauce tanks, cooking wine, salt tanks, equipment and dressings, 904L is a matching steel type for the highly corrosive medium of dilute sulfuric acid.

904L main specifications:

904L seamless pipe, 904L steel plate, 904L round steel, 904L forgings, 904L flange, 904L ring, 904L welded pipe, 904L steel strip, 904L straight bar, 904L wire and supporting welding materials, 904L round cake, 904L flat steel, 904L hexagonal rod, 904L large and small heads, 904L elbow, 904L tee, 904L processing parts, 904L bolts and nuts, 904L fasteners.