SS 202 — Stainless Steel (SS) Grade Specification, Properties & Equivalents
SS 202, also known by its UNS designation S20200, is a popular austenitic chromium-manganese-nickel stainless steel widely utilized across India. It offers a cost-effective alternative to the more common SS 304, achieving similar mechanical properties through a carefully balanced
SS 202, also known by its UNS designation S20200, is a popular austenitic chromium-manganese-nickel stainless steel widely utilized across India. It offers a cost-effective alternative to the more common SS 304, achieving similar mechanical properties through a carefully balanced composition that utilizes higher manganese and nitrogen content while reducing nickel. This makes SS 202 particularly attractive for budget-conscious manufacturers in sectors like kitchenware, architectural fittings, automotive components, and general hardware. Its moderate corrosion resistance is adequate for many everyday applications encountered in the Indian environment, balancing performance with a favorable price point. The widespread availability of SS 202 in various forms across major Indian industrial hubs ensures efficient procurement for fabricators and engineers looking for a versatile and economical stainless steel grade.
Chemical Composition of SS 202
SS 202 Chemical Composition
| Element | % Range |
|---|---|
| Manganese (Mn) | 5.50 - 7.50 |
| Silicon (Si) | ≤ 0.80 |
| Phosphorus (P) | ≤ 0.060 |
| Sulfur (S) | ≤ 0.030 |
| Nickel (Ni) | 3.50 - 5.50 |
| Chromium (Cr) | 17.00 - 19.00 |
| Nitrogen (N) | 0.25 - 0.35 |
| Carbon (C) | ≤ 0.15 |
Mechanical Properties of SS 202
| Property | Value (Typical) |
|---|---|
| Ultimate Tensile Strength (UTS) | 520 - 720 MPa |
| Yield Strength (YS) (0.2% offset) | 240 - 350 MPa |
| Elongation at Break (2 inch) | 35 - 45 % |
| Hardness (Brinell) | ≤ 217 HB |
| Density | ~ 7.9 g/cm³ |
| Modulus of Elasticity | ~ 190-200 GPa |
Available Forms in India for SS 202
| Shape | Typical Sizes | Standard Length |
|---|---|---|
| Sheet & Plate | 0.4mm - 6mm (Coils/Sheets), 3mm - 30mm (Plates) | Up to 3000mm (Sheets), Up to 6000mm (Plates) |
| Bar & Rod | 5mm - 50mm Diameter | Up to 6000mm |
| Wire | 0.5mm - 5mm Diameter | As per customer requirement (Coils) |
| Pipe & Tube | 1/2" - 4" NB (Seamless/Welded) | Up to 6000mm |
Real-world Applications for SS 202
- Kitchenware: SS 202 finds use in manufacturing sinks, utensils, and cookware due to its decent corrosion resistance and aesthetic appeal.
- Architectural: Used for decorative elements, window frames, door handles, and railings where moderate corrosion resistance is sufficient.
- Automotive: Applied in exhaust components and trim parts that require a balance of corrosion resistance and cost-effectiveness.
- Fasteners: Utilized for general-purpose bolts, nuts, and screws in mildly corrosive environments.
- Hospitality: Common in serving trays, trolleys, and food service equipment in hotels and restaurants.
- Appliances: Found in the outer casings and internal components of various home appliances.
Machinability & Weldability of SS 202
Machining SS 202 stainless steel requires attention due to its work-hardening characteristics. While not as challenging as some other alloys, speeds should be moderate, and continuous chip formation is preferred. Using sharp, rigid tools made of high-speed steel or carbides is recommended. Recommended cutting speeds for SS 202 typically range from 15-25 m/min for turning and 10-20 m/min for milling, with liberal use of coolant. Constant feed rates and avoiding dwelling are crucial to prevent excessive hardening of the SS 202 surface. Weldability of SS 202 is considered good, akin to SS 304. It can be readily welded using common methods such as Gas Tungsten Arc Welding (GTAW/TIG), Gas Metal Arc Welding (GMAW/MIG), and Shielded Metal Arc Welding (SMAW). Due to its composition, preheating of SS 202 is generally not necessary. Post-weld heat treatment is usually not required for SS 202 in most applications, as it does not significantly increase susceptibility to corrosion. However, maintaining cleanliness of the weld area is paramount to ensure optimal corrosion resistance of the welded SS 202 joint.Heat Treatment & Processing for SS 202
SS 202 stainless steel, a high-manganese austenitic grade, is primarily hardened by cold working, not by heat treatment. It does not respond to hardening by quenching and tempering like martensitic or precipitation-hardening steels. The typical heat treatment for SS 202 involves annealing to soften the material after cold deformation or to relieve stresses. Annealing temperatures for SS 202 usually range from 1040°C to 1100°C. To maintain the austenitic structure and achieve optimal softness and ductility, this high-temperature annealing must be followed by rapid cooling, typically water quenching. Proper processing of SS 202 involves careful control of temperatures during manufacturing operations. While hot working can be performed, temperatures should be managed to avoid excessive grain growth, typically in the range of 1150°C to 1250°C, followed by annealing. Cold forming operations like bending, drawing, and stamping will increase the strength and hardness of SS 202 due to work hardening. If excessive cold work is performed, a stress-relieving anneal at around 850-900°C or a full anneal may be necessary to restore sufficient ductility for subsequent operations. Thorough cleaning after processing is vital for SS 202 to preserve its corrosion resistance.Sourcing in India for SS 202
SS 202 stainless steel is readily available from major Indian manufacturers like SAIL, Jindal Stainless, and Posco Maharashtra, alongside numerous smaller producers and stockists. Key sourcing hubs include Mumbai, Pune, Chennai, and Ahmedabad, offering substantial inventory. Availability is generally good across common forms such as sheets, plates, bars, and wires. Minimum Order Quantities (MOQs) can vary, with some suppliers offering smaller cut-to-size pieces, while larger orders might attract better pricing. The price band for SS 202 typically ranges from INR 220 to INR 280 per kilogram, depending on the form, quantity, and prevailing market conditions. Mill Test Certificates (MTC) guaranteeing full chemistry and mechanical properties as per the specified standard (e.g., ASTM A240 or IS equivalent) are standard expectation for all procurements of SS 202. PMI (Positive Material Identification) testing is also commonly requested by buyers to verify alloy composition.International Equivalents for SS 202
| Standard | Code |
|---|---|
| ASTM | A240 / UNS S20200 |
| JIS | SUS 202 |
| EN | 1.4057 (similar but not exact) |
| GOST | 12Х18Н10Т (similar but not exact) |
| DIN | X5CrNiMn18-8 (similar but not exact) |
FAQs about SS 202
What is SS 202 stainless steel?
SS 202 is an austenitic stainless steel characterized by its lower nickel content compared to 304, achieved by substituting manganese and nitrogen. This composition provides moderate corrosion resistance, suitable for many general-purpose applications, and offers a cost-effective alternative. Its mechanical properties are comparable to 304, making SS 202 a viable option for various industrial and consumer goods in India where budget is a key consideration. Its availability in common forms facilitates its use across diverse manufacturing sectors.
What is the corrosion resistance of SS 202?
SS 202 stainless steel exhibits good resistance to atmospheric corrosion and many mild chemical environments. However, it is susceptible to pitting and crevice corrosion in chloride-rich environments and stress corrosion cracking at elevated temperatures. For aggressive media, grades like SS 316 are recommended. The performance of SS 202 is generally considered good for indoor and outdoor applications with minimal corrosive elements, typical in many Indian urban settings.
Can SS 202 be welded?
Yes, SS 202 stainless steel is weldable using standard austenitic welding procedures. Techniques like TIG, MIG, and Stick welding can be employed. Due to its higher manganese content, preheating is generally not required, but a post-weld heat treatment is not typically necessary unless specific mechanical properties are critical, which is rare for its common applications. Ensuring clean weld surfaces is important for SS 202 to maintain corrosion resistance.
What are the main advantages of using SS 202?
The primary advantage of SS 202 stainless steel is its cost-effectiveness compared to higher nickel grades like SS 304. By using manganese and nitrogen, manufacturers can achieve similar mechanical strength at a lower material cost. This makes SS 202 an attractive option for high-volume production of items where extreme corrosion resistance isn't the highest priority, such as general hardware, kitchenware, and some architectural components in the Indian market.
How is SS 202 heat treated?
SS 202 stainless steel can be hardened effectively through cold working, similar to other austenitic grades. It does not respond to heat treatment for hardening. Annealing of SS 202 is typically performed at temperatures between 1040-1100°C, followed by rapid quenching to restore ductility and workability. This process is crucial after significant cold deformation to relieve stresses and prepare the SS 202 material for further processing or use.
Tags: grade, stainless steel (ss), ss 202