Hastelloy B3

Hastelloy B3 (N10675) Hastelloy main characteristics and welding and processing:

1. Material analysis: Mechanical properties of Hastelloy B3 (N10675) Hastelloy plate in solid solution state: As the heating temperature increases, its tensile strength, yield strength, and elastic modulus will decrease, while the elongation, thermal expansion coefficient, thermal conductivity, and The specific heat increases slightly; as the cold deformation rate increases, the hardness, tensile strength and yield strength increase, and the elongation decreases.

2. Forming processing characteristics: After analysis, the main forming processing characteristics of Hastelloy B3 are:

(1) The elongation of Hastelloy B3 material is relatively high, which creates favorable conditions for cold press forming.

(2) Hastelloy B3 material is harder than austenitic stainless steel and has a more obvious work hardening tendency, so it requires greater pressure during cold forming, or step-by-step forming.

(3) When the cold forming deformation rate of Hastelloy B3 material is less than 10%, it will not affect the corrosion resistance of the workpiece. However, during the welding process, the presence of residual stress may cause hot cracks in the weld. Therefore, for workpieces that need to be welded later, the influence of residual stress should be eliminated as much as possible.

(4) Cold forming with severe deformation will increase the yield-strength ratio of Hastelloy B3 materials and increase the sensitivity to stress corrosion and cracks. Intermediate and final heat treatment processes are often used.

(5) Hastelloy B3 material is very sensitive to oxidizing media and sulfur, phosphorus, lead and other low melting point metals at high temperatures.

(6) In the 600-800°C range, if the heating time is too long, Hastelloy B3 alloy will produce a brittle phase, resulting in reduced elongation. Moreover, when external force or deformation is limited in this temperature range, hot cracks are prone to occur. Therefore, when using hot forming, the temperature must be controlled above 900°C.

(7) Before processing and pressing the Hastelloy B3 material, the surface of the mold in contact with the workpiece should be cleaned; during cold working, lubrication methods can be used, and degreasing or alkali cleaning must be performed immediately after forming.

(8) After the workpiece comes out of the furnace and is water-cooled, the oxide film on the surface will be thicker and should be fully pickled. If there is an oxide film remaining, cracks may occur during the next pressing; if necessary, sandblasting can be performed before pickling.

3. Welding and forming:

(1) Before forming and processing, if the raw blank needs to be welded, it is best to choose the gas tungsten arc welding (GTAW) welding method, so as to better protect the weld from being oxidized. If the manual arc welding method is used, It is easy to cause the middle weld bead to be oxidized. Even if each layer is polished and cleaned, it is difficult to ensure that the cleaning is complete. There is a fine oxide layer remaining, which may also affect the forming and processing performance of the weld. Before welding the workpiece, attachments and oxide layers on the groove and base metal surfaces must be removed, because the presence of oxide films and impurities will affect the performance of the weld and heat-affected zone. It is best to use a small current for welding, avoid too slow speed, no swing, control the interlayer temperature below 100°C, and use argon gas protection on the front and back sides to avoid high-temperature oxidation and burning of alloy elements. Before pressing, the weld surface should be polished smooth, the thick oxide layer on the weld surface should be removed and pickled. Because the oxide layer of the Hastelloy B3 material weld is very hard and difficult to remove by direct pickling, it is easy to produce fine cracks during the press forming process, which affects the performance of the weld.

(2) The advantage of hot forming is that it can be formed at one time and work hardening can be avoided. If the forming temperature can be controlled well, heat treatment can be eliminated. However, the temperature changes greatly during the hot forming process, and each area is different. Even the surface in direct contact with the mold may be much lower than the temperature inside the metal, which is difficult to measure and control. Once the local material enters the sensitive area during the processing, Temperature zone, micro-cracks and other defects will occur, which will be difficult to eliminate in the later solid solution heat treatment. Drawing on the experience of the processing plant, the cold forming process was chosen. The pressing method is preferably molding. When spinning is necessary, cold spinning or warm spinning with a temperature not exceeding 400°C is used.

(3) During the cold forming process, when the deformation rate is large, the step-by-step forming process should be used. Intermediate heat treatment is required for step-by-step forming. Solution heat treatment should be used and the temperature should be controlled above 1000°C. Choose the solution heat treatment process and the temperature reaches 1060~1080℃. After the workpiece is finally pressed and formed, it must undergo a solid solution heat treatment to eliminate residual stress and avoid affecting the subsequent welding quality.

product

According to drawings or samples

Hastelloy is another family of nickel-based superalloys known for their exceptional corrosion resistance and high-temperature strength. Here's an overview of Hastelloy:

Corrosion Resistance:

Like Inconel, Hastelloy alloys are prized for their outstanding resistance to corrosion in various aggressive environments, including acids, chlorides, sulfides, and oxidizing and reducing conditions. This corrosion resistance makes Hastelloy suitable for use in chemical processing, pollution control, and marine applications.

High Temperature Performance:

Hastelloy alloys maintain their mechanical strength and integrity at elevated temperatures, making them suitable for applications in high-temperature environments such as gas turbines, aerospace components, and industrial furnaces.

Alloying Elements:

Hastelloy alloys are typically composed of nickel as the primary element, along with significant amounts of chromium, molybdenum, and other elements like cobalt, tungsten, and iron. These alloying elements contribute to the alloys' unique properties, including corrosion resistance and high-temperature strength.

Versatility:

Hastelloy alloys are available in various grades, each tailored to specific applications and operating conditions. Common grades include Hastelloy C-276, Hastelloy C-22, Hastelloy X, and Hastelloy B-2, among others. These grades offer a range of properties suitable for different environments and industries.

Applications:

Hastelloy alloys find widespread use in industries such as chemical processing, petrochemical, oil and gas, aerospace, pollution control, and pharmaceuticals. They are employed in equipment such as reactors, heat exchangers, valves, pumps, and piping systems where corrosion resistance and high-temperature performance are critical.

Fabrication:

Hastelloy alloys can be fabricated into various forms, including sheets, plates, bars, wires, tubes, and forgings, allowing for the production of complex components tailored to specific applications.

Overall, Hastelloy alloys are highly regarded for their exceptional corrosion resistance, high-temperature strength, and versatility, making them indispensable materials in industries where harsh environments and demanding operating conditions are common.