Stainless Steel 332 Grade (UNS S33200)
OVERVIEW OF STAINLESS STEEL 332
Stainless Steel 332 is a high-nickel, high-chromium austenitic stainless steel designed for excellent resistance to oxidation, carburization, sulfidation, and corrosion at elevated temperatures.
Key characteristics include:
- Fully austenitic microstructure
- High nickel content (~30–34%) for superior stability and toughness
- Excellent strength retention at high temperatures
- Good resistance to stress corrosion cracking
- Non-magnetic in annealed condition
- Good weldability using appropriate filler metals
This grade is particularly suitable for severe service environments where both heat and corrosive media are present.
CHEMICAL COMPOSITION
| Element | Typical Content (%) |
| Nickel (Ni) | ~31 % |
| Chromium (Cr) | ~20.5 % |
| Manganese (Mn) | ~1 % |
| Silicon (Si) | ~0.4 % |
| Titanium (Ti) | ~0.3 % |
| Aluminum (Al) | ~0.3 % |
| Copper (Cu) | ~0.2 % |
| Carbon (C) | ~0.03 % |
| Phosphorus (P) | ~0.02 % |
| Sulfur (S) | ~0.01 % |
| Iron (Fe) | Balance |
MECHANICAL PROPERTIES
| Property | Value |
| Tensile Strength (UTS) | ~600 MPa (87,000 psi) |
| Yield Strength (0.2% offset) | ~294 MPa |
| Elongation at Break | ~44 % |
| Reduction of Area | ~67 % (from independent source) |
| Hardness (BHN) | ~150–200 BHN |
| Modulus of Elasticity | ~28×10⁶ psi (~193 GPa) |
These figures are typical ranges and may vary with heat treatment, product form, or manufacturing process.
PHYSICAL PROPERTIES
| Property | Approx. Value |
| Density | ~7.8 g/cm³ (~7800 kg/m³) |
| Elastic Modulus | ~190–210 GPa |
| Poisson’s Ratio | ~0.27–0.30 |
AISI 332 MANUFACTURING PROCESS
Stainless Steel 332, an austenitic stainless steel, is manufactured through a process involving melting and refining raw materials to achieve the desired chemical composition. The primary steps include:
Raw Material Selection: High-quality raw materials, mainly iron ore, chromium, nickel, and other alloying elements like manganese, silicon, and molybdenum, are selected based on precise proportions for the desired grade.
- Melting and Refining: The raw materials are melted in an electric arc furnace or an induction furnace at extremely high temperatures, reaching around 1600-1700°C. This process ensures thorough mixing to achieve the specific chemical composition required for Stainless Steel 332.
- Casting: Once molten, the alloy is cast into semi-finished forms like slabs, blooms, or billets using casting methods such as continuous casting or ingot casting.
- Forming and Shaping: The cast semi-finished products are further processed through hot rolling, cold rolling, or forging to achieve the desired dimensions and shapes, like sheets, plates, bars, or tubes.
- Heat Treatment: Heat treatment processes like annealing, quenching, or tempering may be applied to refine the microstructure and enhance mechanical properties like strength, hardness, and ductility.
- Surface Finishing: Various finishing techniques like pickling, passivation, or polishing are used to improve the surface quality, removing impurities and ensuring a clean, smooth finish.
- Quality Control: Stringent quality checks and inspections are carried out throughout the manufacturing process to ensure the material meets industry standards for composition, mechanical properties, and surface finish.
This intricate manufacturing process results in Stainless Steel 332, known for its corrosion resistance, mechanical strength, and suitability for a wide range of industrial applications.
APPLICATIONS
- Furnace parts and heat-treatment equipment
- Radiant tubes, retorts, and muffles
- Heat exchangers and condensers
- Chemical processing equipment
- Petrochemical and refinery components
- High-temperature piping and tubing systems
- Thermal processing baskets and fixtures
- Components exposed to carburizing and sulfidizing atmospheres
- Power generation and industrial heating equipment
AISI 332 CHARACTERISTICS
Stainless Steel 332 boasts several key characteristics that make it highly sought after in various industries:
- Corrosion Resistance: Exceptional resistance to corrosion, particularly in harsh and corrosive environments, thanks to its high chromium and nickel content.
- Durability: Exhibits excellent durability and longevity, making it suitable for applications that require resistance to wear, tear, and degradation over time.
- Strength and Toughness: Maintains good strength and toughness, providing structural integrity and reliability in demanding conditions.
- Heat Resistance: Retains its properties at high temperatures, making it suitable for applications involving elevated temperatures and thermal cycling.
- Formability and Fabrication: Offers good formability and weldability, allowing for various fabrication processes and customization in manufacturing.
- Hygienic Properties: Possesses hygienic qualities, making it suitable for applications in industries like food, pharmaceuticals, and healthcare.
- Aesthetic Appeal: Often appreciated for its aesthetic appeal, lending a clean, polished, and professional look to applications in architecture and design.
WELDING PROCESS OF 332 STAINLESS STEEL
The welding process for Stainless Steel 332, an austenitic stainless steel, typically involves techniques tailored to preserve its corrosion resistance and mechanical properties. Common welding methods include:
- Shielded Metal Arc Welding (SMAW): Utilizes a flux-coated electrode, creating an arc between the electrode and the workpiece. This method is versatile but requires attention to control the heat input to prevent excessive oxidation.
- Gas Tungsten Arc Welding (GTAW/TIG): Involves a non-consumable tungsten electrode, allowing precise control over the welding process. It produces high-quality welds but demands skill to prevent contamination and maintain the alloy's integrity.
- Gas Metal Arc Welding (GMAW/MIG): Uses a consumable wire electrode fed through a welding gun, often in a shielding gas atmosphere. It offers high productivity but requires adequate shielding to prevent oxidation.
- Resistance Spot Welding: Utilizes pressure and electrical resistance to join Stainless Steel 332 sheets or components at specific points. It's commonly used for thin materials in mass production but may require surface preparation to avoid contamination.
Forging process of 332 Stainless steel
The forging process for Stainless Steel 332 involves shaping the alloy into desired forms through controlled application of force and temperature. The steps typically include:
- Billet Preparation: High-quality Stainless Steel 332 is initially heated to a forging temperature, generally around 2150-2350°F (1175-1285°C), to render it malleable for shaping.
- Forming: The heated metal is placed in a forging press or hammer, where controlled force is applied to shape it into the desired form—like bars, blocks, or specific components.
- Reduction: The forged metal is subjected to repeated shaping and compression, reducing its size and adjusting its grain structure for enhanced strength and integrity.
- Heat Treatment: Post-forging, heat treatment processes like annealing or tempering may be applied to refine the microstructure and relieve internal stresses, optimizing mechanical properties.
- Surface Finish: The forged components might undergo surface finishing processes such as machining, grinding, or polishing to achieve precise dimensions and desired surface characteristics.
EQUIVALENT GRADES
| Standard / System | Equivalent / Designation |
| UNS | S33200 |
| AISI | AISI 332 |
| ASTM | ASTM A240 / A276 / A479 (product form dependent) |
| DIN / EN | No direct equivalent |
| JIS | No direct equivalent |
| ISO | Closest match only (no exact equivalent) |
332 stainless steel price
As of my last update in January 2022, Stainless Steel 332, like other stainless steel grades, experienced fluctuations in price influenced by various factors:
- Raw Material Costs: Fluctuations in the prices of raw materials like nickel, chromium, and molybdenum, which are key components of Stainless Steel 332, directly impact its overall price.
- Market Demand: Changes in market demand, influenced by industries such as construction, automotive, oil and gas, and manufacturing, can affect the price of Stainless Steel 332.
- Global Economic Conditions: Economic shifts, trade policies, and geopolitical factors influence the pricing of stainless steel and its grades, including Stainless Steel 332.
- Manufacturing and Processing Costs: Production, processing, and transportation costs also contribute to the final price of Stainless Steel 332.
Due to the ever-changing nature of these factors, the price of Stainless Steel 332 can vary over time. It's advisable to consult industry publications, stainless steel suppliers, or commodity pricing platforms for the most current and accurate pricing information.