Stainless steel type 304 and 321 are amongst a few versatile grades in the family of stainless steel. 321 grade is derived from the SS 304 grade; however, both these modules can be differentiated based on certain key features.
The 304 and 321-grade stainless steel can be differentiated by their titanium content; however, the concentration of carbon is the main differentiating factor. The 321 grade is a higher carbon component having a carbon concentration of 0.08 percent and above. The concentrations give it excellent yield strength while invariably affecting its ductility within the system. The grade is difficult to machine and fabricate, making it difficult to process due to its superior strength. A 304 stainless steel is mild carbon steel having a carbon content of 0.07 or below. This enables the components within this range to be machined and fabricated more easily.
The prices of 304 stainless steel keep increasing every day in India but, the same price in the markets of the US is also soaring fast. The price for stainless steel 304 per square foot in India starts at $2. In the USA, the rates of the same 304 stainless steel start at $5 per square foot.
304 grade shows excellent tolerances against oxidation in intermittent service temperatures up to 870 degrees C. It shows good strength in continuous service of up to 925 degrees C. For corrosion resistance services in water for continuous use it is not recommended for use at temperatures between 425 to 860 degrees C.
The maximum stress the 304 stainless steel can be subjected to is 290mpa. If it surpasses this point, the material is deformed. Any deformation that takes place within the items in this grade is irreversible. The excellent yield strength within this grade is thereby very important in designing structures across different industries.
Stainless steel 304 grade possesses excellent mechanical properties. The grade has a comprehensive strength of 210mpa while exhibiting a tensile strength ranging between 500 to 700mpa. The item within this grade possesses proof stress of 190mpa and can be easily elongated by 45%. Apart from this, they have a hardness of 215 Max HB.
SS 321 and SS 304 grades have near-identical chemical compositions. They have a general composition of carbon, manganese, chromium, silicon, phosphorous, sulfur, nickel, and nitrogen. They can be separated based on certain chemical compositions.
The 304 grade is the most used alloy in home and commercial applications within the stainless steel family. The ability of the items to withstand several corrosive media and acids present in food articles makes them an ideal choice for use in domestic tools. It can be employed in the brewing industry, milking machines, sterilizers, hauling tanks, railroad food carts, containers, and so on. The components from this grade have a high and low-temperature resistance coupled with excellent strength. This allows these modules to be used in refrigerators, stoves, steam tables cream, dispensers, hot pans, flatware, etc.
SS 304 and 316 are amongst the most common and widely used grades of stainless steel. Both these grades can be distinguished based on certain key features.
Service life- Grade 316 is tough and versatile, making it an ideal choice for having higher longevity compared to the 304 grade
Stainless steel 321 and 321h can be dual certified structures that can be distinguished based on certain key features.
SS 304 is an austenitic grade of stainless steel having a high concentration of chromium and nickel. This allows them to withstand oxidative and corrosive media. This grade of items shows excellent forming and welding capacities. They allow for excellent lower temperature service and can be easily cleaned and fabricated, allowing it to maintain an aesthetical appearance.
The content of this concentration varies based on the requirements of the equipment.
304 stainless steel is made up of 18/8 chemical concentration which gives these components excellent resistance to rust while being employed in stress-induced environments. Their excellent toughness enables them to suffice in high and cryogenic temperatures. The high-strength grade of steel is designed with an excellent melting point of 1450 degrees C.
Type 304 or 1.4301 come in three varieties: 304, 304L, and 304H. All these 3 components have similar properties barring their carbon concentration.
Mechanical properties
SS 304 is an austenitic grade which is the most widely used material grade in the stainless steel family. The module is designed with a material density of 8.00g/cm3. This density ensures that different alloys can be constituted within this grade to give it added resistances and strength.
The above data is typical composition ranges and cannot be warranted for design purposes having various functionality
SS 321 plate is a derivate product of the 321 stainless steel grade. These plates can be shipped across different parts of the world and be available with a standard price ranging between $4 to $5 per piece. The thickness and sizes will dictate the overall costs of the different types of plates.
SS 321 material is an austenitic grade material that is designed with a density of 0.286 lbs/in3. Designed with a melting range between 2550 to 2635 degrees F these, modules exhibit an electrical resistivity of 72 Microhm-cm at 20°C. The grade exhibits good mechanical properties, having a minimum yield strength of 30,000psi with a minimum ultimate tensile strength of 75,000psi. They can be readily elongated by a minimum of 40% and have a hardness of 217 Brinell.
321 grade of stainless steel is designed with a yield strength of 205Mpa, exhibiting a tensile strength of 515Mpa. Designed with a maximum hardness of 217 Brinell these, components can be elongated by 40%. The items show superior resistance against corrosion and oxidative systems while having a melting range between 1398 to 1446 degrees C. Apart from, this the components possess a good coefficient of linear thermal expansion and electrical resistivity.
321 stainless steel is an austenitic chromium-nickel component having corrosion resistance properties similar to grade 304 and 304L in the annealed condition. The steel in this grade possesses higher creep resistance properties coupled with excellent stress rupture properties. The non-magnetic grade is ideal for heat resistance services at elevated temperatures.
321 stainless steel is an austenitic 18/8 grade stabilized making use of titanium. The components have a density of 8027 kg/m3. The items across this grade have a modulus of elasticity in the tension of 193Gpa. The density in the alloy enables other components to be added to the system.
Stainless steel components are designed to work in temperatures up to 900 degrees C. The thermal conductivity of these modules at temperatures between 20 to 100 degrees C is 16.3 W/m·KW/. In temperature ranges between 20 to 500 degrees, the thermal conductivity is in the range of 21.4 W/m·KW/.
The price of stainless steel is based on the dimensions and the overall structure of a component. SS 321 plate in India is available in a price range of $4 to $5. The same plate in South Korea can be availed in a price range of $3 to $4.
Stainless steel 321 is a versatile component that shows high resistance against intergranular corrosion. The components are a metal of choice in applications ranging up to 900 degrees C. This enables them to be utilized in heat exchangers, aircraft exhaust manifolds, furnace parts, thermal oxidizers, and heating elements in high-temperature chemical processing equipment. The higher creep-rupture properties make these components ideal for utilization in boilers, refinery equipment, and pressure vessels. This grade of steel is also seen in expansion joints, bellows, and mineral processing systems.