W.Nr.1.4529 Super austenitic stainless steel Alloy 926, N08926

1.4529 (Alloy 926, N08926) Overview of Super Austenitic Stainless Steel:

The Cr content in 1.4529 (N08926) super austenitic stainless steel is usually 14.0-18.0%, and the nickel content is 24.0-26.0%. 1.4529 (N08926) alloy is a nickel-based alloy containing titanium and aluminum. It contains enough chromium to form and maintain a sufficient amount of chromium oxide to protect it under high temperature conditions. It is more resistant to high temperatures than traditional chromium nickel stainless steels such as 304 ; Higher nickel content makes it have better oxidation resistance than standard 18-8 stainless steel, and its oxidation resistance is not inferior to the higher grades with use temperature up to 1900 degrees Fahrenheit (1038 ℃) alloy.

 

Chemical composition of 1.4529 (Alloy 926, N08926) super austenitic stainless steel:

C≤	Si≤	Mn≤	P≤	S≤	Cr	Ni	Mo	N	Cu≤
0.02	0.50	2.0	0.030	0.010	19.0 21.0	24.0 26.0	6.00  7.00	0.15 0.25	1.0 1.5

 

Physical properties of 1.4529 (Alloy 926, N08926) super austenitic stainless steel:

Density: 8.1 g / cm3,

Melting point: 1320-1390 ℃

 

Minimum value of 1.4529 (Alloy 926, N08926) alloy mechanical properties at room temperature:

Tensile strength 650Rm N / mm2,

Yield strength 295 RP0.2 N / mm2,

Elongation A5%: 35.

 

1.4529 (Alloy 926, N08926) Super austenitic stainless steel main characteristics:

1.High resistance to pitting and crevice corrosion in halide media and acid media containing H2S

2. Can effectively resist chloride ion stress corrosion cracking in practical applications

3.Excellent corrosion resistance to various corrosion in ordinary oxidation and reduction environments

4. The mechanical properties are greatly improved compared to Cronifer 1925 LC-Alloy 904 L

5, compared with the same series of nickel content of 18% of the metallurgical stability has been greatly improved

6. Applicable certification for pressure vessel manufacturing (VdTUV-196 ～ 400 ℃ and ASME certification)

 

1.4529 (Alloy 926, N08926) Application range of super austenitic stainless steel

1.4529 (N08926) alloy is a versatile material that can be applied in many industrial fields:

1.Fire-fighting systems, seawater purification systems, hydraulic and irrigation pipeline systems in marine engineering

2. Bleaching pond in cellulose pulp production

3.Polished rods in corrosive oil wells

4.Hose system in marine engineering

5.Pipes, joints, air flow systems, etc. in the production of acid gases

6. Components in FGD system

7.Evaporators, heat exchangers, filters, mixers, etc. in phosphoric acid production

8.Sulfuric acid separation and condensation system

 

Processing and heat treatment of 1.4529 (Alloy 926, N08926) super austenitic stainless steel:

Suitable for cold and hot processing and machining, but because of its high strength, high power processing equipment is required for cold and hot processing.

1. Heating of 1.4529 (N08926) alloy:

(1) The workpiece should be kept clean before and during the heat treatment.

(2) Do not contact sulfur, phosphorus, lead, and other low-melting metals during heat treatment, otherwise the performance of the material will be impaired. Attention should be paid to removing pollutants such as marking paint, temperature indicating paint, colored crayons, lubricants, and fuel.

(3) The lower the sulfur content in the fuel, the better. The sulfur content in natural gas should be less than 0.1%, and the sulfur content in heavy oil should be less than 0.5%.

(4) Considering the need for temperature control and keeping clean, it is best to perform heat treatment in a vacuum furnace or a gas shielded furnace.

(5) It can also be heated in a box furnace or a gas furnace, but the furnace gas must be clean and neutral to slightly oxidizing. It is necessary to avoid the furnace gas fluctuating between oxidizing and reducing. The heating flame cannot be directly Burn to the workpiece.

2. Hot working of 1.4529 (N08926) alloy:

(1) The hot working temperature range of 1.4529 (N08926) alloy is 1200 ℃ ～ 900 ℃, and the cooling method is water quenching or rapid air cooling.

(2) During heating, the material can be directly sent to the furnace that has been warmed up to the maximum working temperature. After sufficient time of heat preservation (60 minutes per 100mm thickness is required), the material is quickly released and heated in the high temperature section of the specified temperature range machining. When the material temperature drops below the hot working temperature, reheating is required.

(3) In order to obtain the best performance, solution treatment should be performed after hot working.

3. Cold working of 1.4529 (N08926) alloy:

(1) Like all austenitic chromium-nickel stainless steels, the 1.4529 (N08926) alloy has a large work hardening rate, so it is necessary to select processing equipment. Cold-worked materials should be in the solution heat-treated state, and intermediate annealing should be performed when the amount of cold work is large.

(2) If the cold working volume is greater than 15%, a second solid solution treatment is required for the workpiece.

 

Heat treatment of Alloy 926 (N08926) alloy:

(1) The solution treatment temperature range of 1.4529 (N08926) alloy is 1150 ° C to 1200 ° C, and the optimum temperature is 1170 ° C.

(2) The cooling method for materials with a thickness of more than 1.5mm is water quenching, and the materials with a thickness of less than 1.5mm can also be quickly air-cooled. If air cooling is used.

(3) During the heat treatment process, the material can be directly fed into the furnace that has been warmed up to the highest working temperature, and the workpiece must be kept clean.

 

Descaling and pickling of 1.4529 (N08926) alloy:

(1) The adhesion of the surface oxide of 1.4529 (N08926) alloy and the welding slag around the weld is stronger than that of low-alloy stainless steel. It is recommended to use fine-grained abrasive belts or fine-grained wheels for grinding.

(2) Before performing acid pickling with HNO3 / HF mixed acid for a proper time and temperature, the oxide film must be carefully ground or salt bath pretreated to break the oxide film.

 

Machining of 1.4529 (N08926) alloy:

1.4529 (N08926) alloy should be machined after heat treatment. Due to the work hardening of the material, it should be processed at a lower cutting speed and re-entry tool than the low-alloy standard austenitic stainless steel. Under the surface.