ASTM SA240 321 Stainless Steel Elilptical Head For Tube and Shell Heat Exchanger
ASTM SA240 is a specification for stainless steel plates, sheets, and strips used in various industrial applications. It provides guidelines for the chemical composition, mechanical properties, and other requirements for stainless steel products.
321 stainless steel is a type of austenitic stainless steel that contains titanium as a stabilizing element. It offers excellent resistance to corrosion, high temperatures, and oxidation. This makes it suitable for applications in industries such as aerospace, chemical processing, and thermal power plants.
An elliptical head, also known as an ellipsoidal head or elliptical dish, is a type of pressure vessel head that has an elliptical shape. It is typically used in the construction of tanks, boilers, and other pressure vessels. The elliptical shape provides a smooth transition between the cylindrical body of the vessel and the head, reducing stress concentrations and improving structural integrity.
When referring to ASTM SA240 321 Stainless Steel Elliptical Head, it means that the elliptical head is made from stainless steel conforming to the ASTM SA240 specification, specifically using grade 321 stainless steel. The head would be manufactured according to the dimensional and tolerances requirements outlined in the ASTM SA240 standard.
Stainless Steel 321 Equivalent Grades
Grade | UNS No | Old British | Euronorm | Swedish SS | Japanese JIS | ||
---|---|---|---|---|---|---|---|
BS | En | No | Name | ||||
321 | S32100 | 321S31 | 58B, 58C | 1.4541 | X6CrNiTi18-10 | 2337 | SUS 321 |
Stainless Steel 321 Chemical Compositions
Grade | C | Mn | Si | P | S | Cr | Mo | Ni | N | Other | |
---|---|---|---|---|---|---|---|---|---|---|---|
321 | min. max | - 0.08 | 2.00 | 0.75 | 0.045 | 0.030 | 17.0 19.0 | - | 9.0 12.0 | 0.10 | Ti×5(C+N) 0.70 |
Stainless Steel 321 Mechanical Properties
Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50 mm) min | Hardness | |
---|---|---|---|---|---|
Rockwell B (HR B) max | Brinell (HB) max | ||||
321 | 515 | 205 | 40 | 95 | 217 |
Stainless Steel 321 Physical Properties
Grade | Density (kg/m3) | Elastic Modulus (GPa) | Mean Coefficient of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat 0-100 °C (J/kg.K) | Electrical Resistivity (nΩ.m) | |||
---|---|---|---|---|---|---|---|---|---|
0-100 °C | 0-315 °C | 0-538 °C | at 100 °C | at 500 °C | |||||
321 | 8027 | 193 | 16.6 | 17.2 | 18.6 | 16.1 | 22.2 | 500 | 720 |
The production process of ASTM SA240 321 stainless steel elliptical head involves several steps:
1. Material selection: The first step is to select the appropriate grade of stainless steel, in this case, ASTM SA240 321, which is a titanium-stabilized austenitic stainless steel known for its excellent corrosion resistance and high temperature strength.
2. Cutting and shaping: The stainless steel plate is cut into a circular shape using a laser cutting machine or other cutting tools. Then, the circular plate is shaped into an elliptical shape using a hydraulic press or other forming equipment. The dimensions and shape of the elliptical head are determined according to the specific requirements and design specifications.
3. Edge trimming: After shaping, the edges of the elliptical head are trimmed to ensure smooth and even edges. This can be done using a grinding machine or other trimming tools.
4. Heat treatment: The elliptical head is then subjected to a heat treatment process to improve its mechanical properties and remove any residual stresses. This typically involves heating the head to a specific temperature and holding it at that temperature for a certain period of time, followed by controlled cooling.
5. Surface treatment: The surface of the elliptical head is treated to enhance its appearance and protect it from corrosion. This can involve processes such as pickling, passivation, or electro-polishing, depending on the desired finish and application requirements.
6. Inspection and testing: The finished elliptical head undergoes rigorous inspection and testing to ensure its quality and conformance to the required specifications. This may include visual inspection, dimensional checks, hardness testing, and non-destructive testing methods such as ultrasonic or magnetic particle testing.
7. Packaging and shipping: Finally, the ASTM SA240 321 stainless steel elliptical head is carefully packaged to protect it during transportation and shipped to the customer or the next stage of the production process.
The production process of ASTM SA240 321 stainless steel elliptical head involves cutting, shaping, edge trimming, heat treatment, surface treatment, inspection, and packaging. These steps ensure the production of high-quality elliptical heads that meet the required standards and specifications.