Hastelloy and Nickel Based Alloy
1. Corrosion resisting property: Hastelloy C-276 alloy is a nickel - chromium - molybdenum alloy containing tungsten, silicon carbon content is extremely low, which is considered corrosion resistant alloy. The main resistance is wet chlorine, various oxidizing chloride, chloride, sulfate and oxidizing salt, corrosion resistance in low temperature and medium temperature in hydrochloric acid are very good. Therefore, since the past thirty years, in the harsh corrosive environment, such as chemical industry, petroleum chemical industry, flue gas desulfurization, pulp and paper, environmental protection and other industrial fields, it has a wide application.
This alloy has the following characteristics:
① In the oxidation and reduction atmosphere condition, it has excellent corrosion resistance to most corrosive medium.
② It has excellent resistance to pitting corrosion, crevice corrosion and stress corrosion resistance. High Mo, Cr content of the alloy can resistance to chlorine ion corrosion, W element enhanced the corrosion resistance. At the same time, Hastelloy C-276 alloy is only several resistance to wet chlorine, hypochlorite and chlorine dioxide solution corrosion of materials, chloride in high salt concentration solution such as ferric chloride and copper chloride has significant corrosion resistance. Applicable to various concentrations of sulfuric acid solution, is one of a few can be applied to hot concentrated sulfuric acid solution.
2. Physical property:
The physical properties of Hastelloy C-276 alloy are as follows:
Material composition: 57Ni-16Cr-16Mo-5Fe-4W-2.5Co*-1Mn*-0.35V*-0.08Si*-0.01C* *
Executive standard: UNS N10276, ASTM B575, ASME SB575, DIN/EN 2.4819
Density: 8.90g/cm3
3. Mechanical property:
Tensile strength: σb≥730Mpa, extensibility: δ≥40%, hardness: HRB≤100.
Hastelloy C-276 alloy hot forming is annealed immediately at 1150 degrees, and water to quench. Cold deformation processing will make its strength increase of Hastelloy C-276 alloy.
Hastelloy C-276 alloy and ordinary austenitic stainless steel has similar forming performance. But because of its better than ordinary austenitic stainless steel strength, so, in the cold forming process will have more stress. In addition, the hardening speed of this material is much faster than ordinary stainless steel, so in a wide cold forming process, it should take midway annealing treatment.
4. Welding and heat treatment:
C-276 alloy welding performance is similar to ordinary austenitic stainless steel, in the use of a welding method of C-276 before welding, it must take measures to make the corrosion resistance of weld and heat affected zone decreased. For example the gas tungsten arc welding (GTAW), metal gas arc welding, submerged arc welding (GMAW) or some other can make the drop zone corrosion resistance minimum welding method of welding seam and heat affected.
On the choice of the form of welded joint, it can refer to the ASME boiler and pressure vessel code successful experience on welding joint of Hastelloy C-276 alloy.
It is best to use the mechanical processing method of welding groove, but mechanical processing will bring the work hardening, so the machining groove grinding is necessary before welding.
Welding should be used when appropriate heat input speed, to prevent thermal cracks. In the vast majority of corrosive environment, Hastelloy C-276 alloy can be welded to the application form.
But in a very harsh environment, C-276 materials and welding parts to carry on the solution heat treatment to obtain the best corrosion resistance.
The welding of hastelloy C-276 alloy can choose their own welding welding material or filler metal.
Hastelloy C-276 alloy solid solution heat treatment process includes two processes: A: Heating at 1040 degrees ~1150 degrees, B: in two minutes, rapid cooling to black state (about 400 DEG C), thus treated materials have good corrosion resistance. Therefore only the HA's C-276 alloy stress relieving heat treatment is invalid. Before the heat treatment, all the dirt cleaning alloy surface pollution, may produce carbon during heat treatment.
During welding or heat treatment, Ha's C-276 alloy surface will produce the oxide to reduce the Cr content in the alloy, and impact corrosion resistance, so the surface need to be cleaned. You can use stainless steel wire brush or grinding wheel, pickling liquid mixture and then dip appropriate proportion of nitric acid and hydrofluoric acid, then rinse with water.
5. Application area:
Petrochemical equipment, heat exchanger, flue gas desulfurization equipment, fluid chemical pump, fluorine chemical industry.
This alloy has the following characteristics:
① In the oxidation and reduction atmosphere condition, it has excellent corrosion resistance to most corrosive medium.
② It has excellent resistance to pitting corrosion, crevice corrosion and stress corrosion resistance. High Mo, Cr content of the alloy can resistance to chlorine ion corrosion, W element enhanced the corrosion resistance. At the same time, Hastelloy C-276 alloy is only several resistance to wet chlorine, hypochlorite and chlorine dioxide solution corrosion of materials, chloride in high salt concentration solution such as ferric chloride and copper chloride has significant corrosion resistance. Applicable to various concentrations of sulfuric acid solution, is one of a few can be applied to hot concentrated sulfuric acid solution.
2. Physical property:
The physical properties of Hastelloy C-276 alloy are as follows:
Material composition: 57Ni-16Cr-16Mo-5Fe-4W-2.5Co*-1Mn*-0.35V*-0.08Si*-0.01C* *
Executive standard: UNS N10276, ASTM B575, ASME SB575, DIN/EN 2.4819
Density: 8.90g/cm3
3. Mechanical property:
Tensile strength: σb≥730Mpa, extensibility: δ≥40%, hardness: HRB≤100.
Hastelloy C-276 alloy hot forming is annealed immediately at 1150 degrees, and water to quench. Cold deformation processing will make its strength increase of Hastelloy C-276 alloy.
Hastelloy C-276 alloy and ordinary austenitic stainless steel has similar forming performance. But because of its better than ordinary austenitic stainless steel strength, so, in the cold forming process will have more stress. In addition, the hardening speed of this material is much faster than ordinary stainless steel, so in a wide cold forming process, it should take midway annealing treatment.
4. Welding and heat treatment:
C-276 alloy welding performance is similar to ordinary austenitic stainless steel, in the use of a welding method of C-276 before welding, it must take measures to make the corrosion resistance of weld and heat affected zone decreased. For example the gas tungsten arc welding (GTAW), metal gas arc welding, submerged arc welding (GMAW) or some other can make the drop zone corrosion resistance minimum welding method of welding seam and heat affected.
On the choice of the form of welded joint, it can refer to the ASME boiler and pressure vessel code successful experience on welding joint of Hastelloy C-276 alloy.
It is best to use the mechanical processing method of welding groove, but mechanical processing will bring the work hardening, so the machining groove grinding is necessary before welding.
Welding should be used when appropriate heat input speed, to prevent thermal cracks. In the vast majority of corrosive environment, Hastelloy C-276 alloy can be welded to the application form.
But in a very harsh environment, C-276 materials and welding parts to carry on the solution heat treatment to obtain the best corrosion resistance.
The welding of hastelloy C-276 alloy can choose their own welding welding material or filler metal.
Hastelloy C-276 alloy solid solution heat treatment process includes two processes: A: Heating at 1040 degrees ~1150 degrees, B: in two minutes, rapid cooling to black state (about 400 DEG C), thus treated materials have good corrosion resistance. Therefore only the HA's C-276 alloy stress relieving heat treatment is invalid. Before the heat treatment, all the dirt cleaning alloy surface pollution, may produce carbon during heat treatment.
During welding or heat treatment, Ha's C-276 alloy surface will produce the oxide to reduce the Cr content in the alloy, and impact corrosion resistance, so the surface need to be cleaned. You can use stainless steel wire brush or grinding wheel, pickling liquid mixture and then dip appropriate proportion of nitric acid and hydrofluoric acid, then rinse with water.
5. Application area:
Petrochemical equipment, heat exchanger, flue gas desulfurization equipment, fluid chemical pump, fluorine chemical industry.
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