Incoloy800HT nickel-based alloy
Incoloy800HT
Quantity:
Data grade: Incoloy800HT nickel-based alloy
American brand: UNS NO8811
German brand: W.Nr.1.4876
1. Overview of Incoloy800HT (N08811) nickel-based alloy:
Incoloy800HT (N08811) is a fully austenitic low-carbon nickel-iron-chromium alloy in the same series as Incoloy 800. The cobalt content in the alloy can be strictly controlled below 0.01%.
Incoloy800HT (N08811) is resistant to many corrosive media. Its higher content gives it good resistance to stress corrosion cracking in aqueous corrosive conditions. The high chromium content makes it more resistant to pitting corrosion and crevice corrosion cracking. This alloy has good corrosion resistance to nitric acid and organic acids, but has limited corrosion resistance in sulfuric acid and hydrochloric acid.
In addition to the possibility of pitting corrosion in halides, it has good corrosion resistance in oxidizing and non-oxidizing salts. It also has good corrosion resistance in water, steam and mixtures of steam, air and carbon dioxide. Used in nitric acid condensers, resistant to nitric acid corrosion, steam heating, good mechanical performance, heating element tubes, good mechanical performance, etc. For applications in environments up to 500°C, the alloy is supplied in the annealed condition.
Incoloy800HT (N08811) nickel-based alloy has the following characteristics:
1. Excellent corrosion resistance in extremely high temperature aqueous media up to 500°C.
2. Very good resistance to stress corrosion.
3. Very good processability.
Incoloy800HT (N08811) is a fully austenitic low-carbon nickel-iron-chromium alloy in the same series as Incoloy 800. The cobalt content in the alloy can be strictly controlled below 0.01%.
Incoloy800HT (N08811) is resistant to many corrosive media. Its higher content gives it good resistance to stress corrosion cracking in aqueous corrosive conditions. The high chromium content makes it more resistant to pitting corrosion and crevice corrosion cracking. This alloy has good corrosion resistance to nitric acid and organic acids, but has limited corrosion resistance in sulfuric acid and hydrochloric acid.
In addition to the possibility of pitting corrosion in halides, it has good corrosion resistance in oxidizing and non-oxidizing salts. It also has good corrosion resistance in water, steam and mixtures of steam, air and carbon dioxide. Used in nitric acid condensers, resistant to nitric acid corrosion, steam heating, good mechanical performance, heating element tubes, good mechanical performance, etc. For applications in environments up to 500°C, the alloy is supplied in the annealed condition.
Incoloy800HT (N08811) nickel-based alloy has the following characteristics:
1. Excellent corrosion resistance in extremely high temperature aqueous media up to 500°C.
2. Very good resistance to stress corrosion.
3. Very good processability.
2. Chemical composition of Incoloy800HT (N08811) nickel-based alloy: %
| C≤ | Si≤ | Mn≤ | P≤ | S≤ | Cr≥ | Ni≥ | Mo≥ | Cu≤ | |||||
| 0.06-0.10 | 1.00 | 1.50 | 0.035 | 0.015 | 19.0-23.0 | 30.0-35.0 | - | - | |||||
| other | Al+Ti | Al≤ | Ti≤ | Fe≤ | Co≤ | V≤ | W≤ | Nb≤ | |||||
| 0.85-1.20 | 0.15-0.60 | 0.15-0.60 | 39.5 | - | - | - | - | ||||||
3. Incoloy800HT (N08811) nickel-based alloy grades and standards:
| Grades and standards | Material grade | technical specifications | |||||||||||
| chemical composition | pipes | plate | Rod | strip | Welding wire | Forgings | |||||||
| Seamless tube | welded pipe | ||||||||||||
| German DIN | W.Nr.1.4876 X10NiCrAITi3220 | 17744 432/2 | 17751 432/2 | 17750 432/1 | 17752 432/3 | 17750 432/1 | 17754 432/3 | ||||||
| French AFNOR | Z8NC32.21 | ||||||||||||
| British BS | NA15 | 3074 | 3072 | 3076 | 3073 | ||||||||
| ASTMASMEAMS, USA | Incoloy800HT UNS NO8811 | B423 SB423 | B163 B704 B705 SB163 | B424 SB424 | B425 SB425 | B424 SB424 | |||||||
| ISO | FeNi32Cr21AITi | ||||||||||||
| product | ASTM | ||||||||||||
| rod and bar | B 408 | ||||||||||||
| Plate, sheet and strip | A 240, A 480, B 409, B 906 | ||||||||||||
| Seamless pipes and fittings | B 407, B 829 | ||||||||||||
| Welded nominal pipe | B 514, B 775 | ||||||||||||
| welded pipe | B 515, B 751 | ||||||||||||
| Welded pipe fittings | B 366 | ||||||||||||
| Forgings | B 564 | ||||||||||||
4. Physical properties of Incoloy800HT (N08811) nickel-based alloy:
1. Density: ρ=8.0g/cm3.
2. Melting temperature range: 1350-1400℃.
2. Melting temperature range: 1350-1400℃.
| Temperature℃ | Specific heat capacity J/Kg K | thermal conductivity w/mK | Resistivity uQcm | Elastic modulus KN/mm2 | Thermal expansion coefficient 10-6/K | ||||||||
| 20 | 440 | 10.8 | 112 | 195 | |||||||||
| 93 | |||||||||||||
| 100 | 462 | 12.4 | 114 | 190 | 14.1 | ||||||||
| 200 | 488 | 14.1 | 118 | 185 | 14.9 | ||||||||
| 204 | |||||||||||||
| 300 | 514 | 15.6 | 120 | 179 | 15.2 | ||||||||
| 316 | |||||||||||||
| 400 | 540 | 16.9 | 124 | 174 | 15.6 | ||||||||
| 427 | |||||||||||||
| 500 | 565 | 18.3 | 126 | 168 | 15.8 | ||||||||
| 538 | |||||||||||||
| 600 | 590 | 19.6 | 126 | 161 | 16 | ||||||||
| 649 | |||||||||||||
| 700 | 615 | 21.0 | 127 | 154 | 16.7 | ||||||||
| 760 | |||||||||||||
| 800 | 655 | 23.2 | 128 | 142 | 17.2 | ||||||||
| 871 | |||||||||||||
| 900 | 680 | 25.7 | 129 | 130 | 17.6 | ||||||||
| 982 | |||||||||||||
| 1000 | 710 | 28.1 | 130 | 119 | 17.9 | ||||||||
5. Mechanical performance of Incoloy800HT (N08811) nickel-based alloy: (minimum value of mechanical performance detected at 20°C).
The properties listed in the table below apply to the specified specifications of Incoloy800HT alloy after softening annealing (stabilization annealing). Special capabilities in non-standard size materials can be provided based on the requirements of specific applications.
1. Mechanical performance at room temperature (minimum value):
The properties listed in the table below apply to the specified specifications of Incoloy800HT alloy after softening annealing (stabilization annealing). Special capabilities in non-standard size materials can be provided based on the requirements of specific applications.
1. Mechanical performance at room temperature (minimum value):
| product | Dimensions mm | Yield strength RP0.2 N/mm2 | Yield strength RP1.0 N/mm3 | tensile strength Rm N/mm2 | Elongation A50% | Brinell hardness HB | |||||||
| Thin sheet and strip/cold rolling Plate/hot rolled | 0.5-6.4 | 240 | 265 | 585 | 30 | ≤200 | |||||||
| 5-100 | 135-165 | ||||||||||||
| Rod Cold working Thermal processing | 1.6-64 | ||||||||||||
| 25-100 | |||||||||||||
| >100-240 | 220 | 250 | 550 | 35 | |||||||||
| pipes Cold working Thermal processing | 64-240 | 180 | - | 530 | 30 | ||||||||
| 5-100 | 240 | 265 | 585 | 30 | |||||||||
| Condensing and heat exchangers | 16-76 | ||||||||||||
2. Mechanical performance at room temperature (minimum value):
| product | Yield strength RP0.2 N/mm2 | Yield strength RP1.0 N/mm3 | |||||||||||
| Temperature℃ | 100 | 200 | 300 | 400 | 100 | 200 | 300 | 400 | |||||
| Plate, strip, tube | 205 | 180 | 170 | 160 | 235 | 205 | 195 | 185 | |||||
| Great | 190 | 165 | 155 | 145 | 220 | 190 | 180 | 170 | |||||
3. Incoloy800HT (N08811) ISO V-notch impact test:
Average room temperature: axial direction＞=150J/cm2, radial direction＞=100J/cm2, time-temperature-sensitization curve.
4. Conditional stress value of Incoloy800HT (N08811) alloy:
High condition stress values of 90% yield strength can be used in applications where slightly larger deformations are allowed. These stresses cause permanent stresses that can lead to dimensional changes and are not recommended for flange and gasket connections.
5, Incoloy800HT (N08811) alloy metallographic structure:
Incoloy800HT alloy has a stable face-centered cubic structure. The chemical composition and appropriate heat treatment ensure that the corrosion resistance is not compromised by sensitization.
6. Corrosion resistance of Incoloy800HT (N08811) alloy:
Incoloy800HT is a general engineering alloy that is resistant to acid and alkali metal corrosion in both oxidizing and reducing environments. The high nickel content gives the alloy effective resistance to stress corrosion cracking. It has good corrosion resistance in various media, such as sulfuric acid, phosphoric acid, nitric acid and organic acids, alkali metals such as sodium hydroxide, potassium oxide and hydrochloric acid solution. The higher comprehensive performance of Incoloy800HT is reflected in the nuclear combustion dissolver with various corrosive media, such as sulfuric acid, nitric acid and sodium hydroxide, which are all processed in the same equipment.
High condition stress values of 90% yield strength can be used in applications where slightly larger deformations are allowed. These stresses cause permanent stresses that can lead to dimensional changes and are not recommended for flange and gasket connections.
5, Incoloy800HT (N08811) alloy metallographic structure:
Incoloy800HT alloy has a stable face-centered cubic structure. The chemical composition and appropriate heat treatment ensure that the corrosion resistance is not compromised by sensitization.
6. Corrosion resistance of Incoloy800HT (N08811) alloy:
Incoloy800HT is a general engineering alloy that is resistant to acid and alkali metal corrosion in both oxidizing and reducing environments. The high nickel content gives the alloy effective resistance to stress corrosion cracking. It has good corrosion resistance in various media, such as sulfuric acid, phosphoric acid, nitric acid and organic acids, alkali metals such as sodium hydroxide, potassium oxide and hydrochloric acid solution. The higher comprehensive performance of Incoloy800HT is reflected in the nuclear combustion dissolver with various corrosive media, such as sulfuric acid, nitric acid and sodium hydroxide, which are all processed in the same equipment.
6. Incoloy800HT (N08811) alloy processing and heat treatment:
1. Incoloy800HT (N08811) alloy heating:
(1) The workpiece should always be kept clean before and during heat treatment.
(2) During the heat treatment process, do not come into contact with sulfur, phosphorus, lead and other low-melting point metals, otherwise the performance of the material will be damaged. Pay attention to removing contaminants such as marking paint, temperature indicating paint, colored crayons, lubricating oil, fuel and other contaminants.
(3) The lower the sulfur content in fuel, the better. The sulfur content in gas should be less than 0.1%, and the sulfur content in heavy oil should be less than 0.5%.
(4) Considering the needs of temperature control and maintenance of cleanliness, it is best to perform heat treatment in a vacuum furnace or gas protective furnace.
(5) Heating can also be done in a box furnace or gas furnace, but the furnace gas must be clean and preferably neutral to oxidizing. The furnace gas should be avoided from fluctuating between oxidizing and reducing properties. The heating flame cannot be directly Burning towards the workpiece.
2. Incoloy800HT (N08811) alloy thermal processing:
(1) The thermal processing temperature range of Incoloy 800HT is 1200℃~900℃, and the cooling pipe is water quenched or cooled as quickly as possible between 760℃~540℃. Hot bending should be performed between 1150°C-1000°C.
(2) In order to obtain the best corrosion resistance and creep resistance, annealing treatment must be carried out after hot processing.
(3) The material can be directly fed into the furnace that has been heated to 1200°C. The heat preservation time of the material is 60 minutes per 100mm thickness. After being kept warm for a sufficient time, it is quickly released from the oven and thermally processed within the specified temperature range. When the material temperature drops below the thermal processing temperature, it needs to be reheated.
3. Incoloy800HT (N08811) alloy cold processing:
(1) The work hardening rate of |ncoloy 800HT is greater than that of austenitic stainless steel, so processing equipment needs to be selected. Cold worked materials should be in an annealed heat treatment state, and intermediate annealing should be performed during cold working.
(2) If the amount of cold working is greater than 10%, the workpiece needs to be softened and annealed before use."
4. Incoloy800HT (N08811) alloy heat treatment:
(1) The softening annealing temperature range of Incoloy 800HT is 920℃~980℃, and the optimal processing temperature is 950℃
(2) In order to obtain the best corrosion resistance, the cooling pipes are quenched with water, and materials with a thickness less than 1.5mm can also be quickly air-cooled.
(3) During the heat treatment process, the aforementioned matters that must be kept clean during the heating process must be followed.
5. Incoloy800HT (N08811) alloy descaling and pickling:
(1) The surface oxide of Incoloy 800HT and the adhesion of the welding slag around the weld are stronger than that of stainless steel. Both mechanical and chemical methods can be used. When choosing the mechanical method, avoid metal contamination or surface deformation. method.
(2) Before pickling with HNO3/HF mixed acid, the oxide film must be broken up by careful grinding or salt bath pretreatment."
6. Incoloy800HT (N08811) alloy machining:
Incoloy 800HT must be machined after annealing heat treatment. Due to the work hardening of the material, it is advisable to use lower cutting speeds and heavy feeds than when processing low-alloy standard austenitic stainless steel to machine into the cold-hardened surface layer. under.
7. Incoloy800HT (N08811) alloy welding:
1. Incoloy800HT (N08811) alloy is suitable for welding using any traditional welding process:
Such as tungsten electrode inert gas shielded welding, plasma arc welding, manual sub-arc welding, metal pole inert gas shielded welding, melting pole inert gas shielded welding, shielded gas arc welding, etc. Welding of Incoloy 800HT must be carried out in the annealed state and clean of stains, dust and various marks. Use low heat input, and the interlayer temperature does not exceed 150°C. No pre- or post-weld heat treatment is required.
2. Incoloy800HT (N08811) alloy cleaning:
Remove scale, oil stains and various marks and marks, and clean the base metal and filler alloy (such as welding rod) in the welding area with ketone. Be careful not to use trichlorethylene TRI, perchlorethylene PER and tetrachloride TETRA.
3. Incoloy800HT (N08811) alloy edge preparation:
It is best to use machining, such as turning, milling, planing, or plasma cutting. If the latter is used, the cutting edge (welding surface) must be ground clean and flat, and fine grinding without overheating is allowed. The base metal on both sides of the weld is An area approximately 25mm wide should be sanded until bright metal is exposed.
4. Incoloy800HT (N08811) alloy bevel angle:
Compared with carbon steel, the physical properties of nickel-based alloys and special stainless steels are mainly characterized by low thermal conductivity and high expansion coefficient. These characteristics must be considered when preparing welding grooves, including widening the bottom gap (1~ 3mm), and due to the viscosity of molten gold, a larger groove angle (60~70°) should be used during butt welding to offset the shrinkage of the material.
5. Incoloy800HT (N08811) alloy arc starting:
The arc cannot be started on the surface of the workpiece. The arc should be started on the welding surface to prevent corrosion caused by the arc starting point.
6. Incoloy800HT (N08811) alloy welding process:
(1) Incoloy800HT is suitable for welding with the same material or other metals using any traditional welding process, such as tungsten electrode inert gas shielded welding, plasma arc welding, manual sub-arc welding, metal pole inert gas shielded welding, and melting pole inert gas shielded welding. Among them, pulsed arc welding is the preferred option. When using manual arc welding, it is recommended to use a protective gas mixed with (Ar+He+H2+CO2).
(2) The welding of lncoloy800HT must be carried out in the annealed state, and a stainless steel wire brush should be used to clean away dirt, dust and brand marks. When welding the root of the weld, in order to obtain the best quality of the root weld, the operation must be very careful (xenon 99,99) so that no oxides are produced in the weld after the root welding. The color produced in the welding heat affected zone should be brushed away with a stainless steel brush before the weld area is cooled.
Recommended welding materials: electrode: EniCrFe-3, welding wire: ERNiCr-3.
(3) Incoloy800HT welding parameters and effects (heat input):
Welding operations should be carried out at low heat input specified in the heat input table, using bead weld technology, and the interpass temperature should not exceed 120°C. Welding specifications must be followed. The heat input Q is calculated according to the following formula:
Compared with carbon steel, the physical properties of nickel-based alloys and special stainless steels are mainly characterized by low thermal conductivity and high expansion coefficient. These characteristics must be considered when preparing welding grooves, including widening the bottom gap (1~ 3mm), and due to the viscosity of molten gold, a larger groove angle (60~70°) should be used during butt welding to offset the shrinkage of the material.
5. Incoloy800HT (N08811) alloy arc starting:
The arc cannot be started on the surface of the workpiece. The arc should be started on the welding surface to prevent corrosion caused by the arc starting point.
6. Incoloy800HT (N08811) alloy welding process:
(1) Incoloy800HT is suitable for welding with the same material or other metals using any traditional welding process, such as tungsten electrode inert gas shielded welding, plasma arc welding, manual sub-arc welding, metal pole inert gas shielded welding, and melting pole inert gas shielded welding. Among them, pulsed arc welding is the preferred option. When using manual arc welding, it is recommended to use a protective gas mixed with (Ar+He+H2+CO2).
(2) The welding of lncoloy800HT must be carried out in the annealed state, and a stainless steel wire brush should be used to clean away dirt, dust and brand marks. When welding the root of the weld, in order to obtain the best quality of the root weld, the operation must be very careful (xenon 99,99) so that no oxides are produced in the weld after the root welding. The color produced in the welding heat affected zone should be brushed away with a stainless steel brush before the weld area is cooled.
Recommended welding materials: electrode: EniCrFe-3, welding wire: ERNiCr-3.
(3) Incoloy800HT welding parameters and effects (heat input):
Welding operations should be carried out at low heat input specified in the heat input table, using bead weld technology, and the interpass temperature should not exceed 120°C. Welding specifications must be followed. The heat input Q is calculated according to the following formula:
 | U=arc voltage, volts | ||
| I = welding current, amperes | |||
| V=Welding speed, cm/min. | |||
7. Incoloy800HT (N08811) alloy post-weld treatment (pickling, brushing to remove oxides and heat treatment):
Stainless steel wire brushes should be used to remove oxides immediately after welding, that is to say, brushing should be done when the metal has not yet produced the welding color, so that the ideal surface quality can be obtained without the need for pickling. If there are no special requirements or regulations, pickling is usually the last process in welding. Please refer to the section on descaling and pickling. No heat treatment is required before or after welding.
Stainless steel wire brushes should be used to remove oxides immediately after welding, that is to say, brushing should be done when the metal has not yet produced the welding color, so that the ideal surface quality can be obtained without the need for pickling. If there are no special requirements or regulations, pickling is usually the last process in welding. Please refer to the section on descaling and pickling. No heat treatment is required before or after welding.
8. Application scope of Incoloy800HT (N08811) alloy:
Incoloy800HT is widely used in various industrial fields where the operating temperature does not exceed 550℃. Typical applications are:
1. Heating tubes, containers, baskets and chains used in sulfuric acid pickling factories.
2. Seawater cooling heat exchanger, marine product pipeline system, acid gas environment pipeline
3. Heat exchangers, evaporators, washing, dipping tubes, etc. in phosphoric acid production.
4. Air heat exchanger in petroleum refining.
5. Food engineering and chemical process.
6. Flame-retardant alloys for high-pressure oxygen applications
9. Varieties, specifications and supply status of Incoloy800HT (N08811) nickel-based alloy:
Shanghai Disheng Special Alloy can produce various specifications of Incoloy800HT seamless pipes, Incoloy800HT steel plates, Incoloy800HT round bars, Incoloy800HT forgings, Incoloy800HT flanges, Incoloy800HT rings, Incoloy800HT welded pipes, Incoloy800HT steel strips, Incoloy800HT wires and supporting welding materials.
| Variety classification | delivery status | ||||||||||||
| Seamless tube | Solid solution + acid white, length can be customized | ||||||||||||
| plate | Solid solution, pickling, trimming | ||||||||||||
| welded pipe | Solid solution acid whitening + RT% flaw detection | ||||||||||||
| Forgings | Annealing + polishing | ||||||||||||
| Rod | Forged state, surface polished or polished | ||||||||||||
| strip | Cold rolled, solid solution soft state, descaled delivery | ||||||||||||
| wire material | Delivered in solid solution pickled disc shape or straight strip shape, solid solution straight strip in fine polished state | ||||||||||||
Note: Incoloy and 800HT™ are registered trademarks of Specialty Metals Group, Inc.
