austenitic 304 बनाम 316 stainless steel are often referred to as surgical or medical-grade stainless steels and are among the most commonly used.
The primary distinction between 304 और 316 stainless steel lies in the addition of molybdenum to 316, which significantly enhances its corrosion resistance, particularly in saline or chloride-rich environments.
So, how do you decide between them? इस आलेख में, we’ll break down their properties, similarities, and differences to help you make the right choice.
1. क्या है 304 स्टेनलेस स्टील?
304 stainless steel or 304 SS is austenitic grade steel that contains 18% chromium and 8% निकल (hence the name 18/8) and other alloying elements such as carbon, फास्फोरस, गंधक, सिलिकॉन, and manganese.
304 stainless steel is one of the most popular and versatile stainless steels available. It is part of the austenitic family, meaning it has a face-centered cubic crystal structure, which contributes to its excellent corrosion resistance and high formability.
Physical and mechanical properties：
- घनत्व: The density of 304 stainless steel is 7.93 g/cm g.
- Tensile strength: Tensile strength (σb) ≥ 520 एमपीए.
- Conditional yield strength: Conditional yield strength (σ0.2) ≥ 205 एमपीए.
- Elongation: बढ़ाव (%) ≥ 40.
- Hardness: The hardness value is different under different test methods, उदाहरण के लिए, the hardness value is 187 मॉडिफ़ाइड अमेरिकन प्लान; 90 HRB; और 200 एचवी.
- Melting point: The melting point is between 1398-1454℃.
- Specific heat capacity: The specific heat capacity is 0.50 KJ/kg·K.
- Thermal conductivity: The thermal conductivity is 16.3 W/m·K at 20℃ and 21.5 W/m·K at 500℃.
- Linear expansion coefficient: The linear expansion coefficient is 17.2×10^-6/℃ at 0-100℃ and 18.4×10^-6/℃ at 0-500℃.
- Resistivity: The resistivity is 0.73×10^-6 Ω·m.
304 stainless steel has a wide range of applications, as follows:
- Architectural decoration: 304 stainless steel has good corrosion resistance and aesthetics, and is widely used in the manufacture of architectural decoration materials, such as doors, खिंचाव, railings, stair handrails, वगैरह.
- Petrochemical industry: 304 stainless steel has good corrosion resistance and high-temperature strength, and is used in chemical equipment, containers, and pipelines in the petrochemical industry.
- Food processing: 304 stainless steel is non-toxic, odorless, and does not produce harmful substances.
It is widely used in food processing, storage, and transportation, such as beverage production equipment, food storage containers, food processing machinery, वगैरह. - Medical equipment: 304 stainless steel has good corrosion resistance, non-toxicity, and glossiness, and is widely used in the manufacture of medical equipment, such as surgical instruments, orthopedic implants, वगैरह.
- Automobile manufacturing: 304 stainless steel has good corrosion resistance and wear resistance, and is used in exhaust pipes, fuel pipes, द्वार, खिंचाव, bodies, and other parts in automobile manufacturing.
- Household items: 304 stainless steel has good corrosion resistance and aesthetics, and is widely used in the manufacture of kitchen utensils, such as pots, bowls, plates, knives, forks, वगैरह.
It is also used in the manufacture of bathroom supplies, such as faucets, bathtubs, toilets, वगैरह.
इसके अलावा, 304 stainless steel is also used in furniture manufacturing, such as sofas, beds, chairs, वगैरह।; building materials; chemical industry; agricultural equipment; ship parts and other fields.
Its excellent corrosion resistance, गर्मी प्रतिरोध, low-temperature strength, and mechanical properties, as well as good processability and weldability, make 304 stainless steel an ideal choice for many industrial and household applications.
2. क्या है 316 स्टेनलेस स्टील?
316 stainless steel or 316 SS is the second most popular austenitic grade of stainless steel, and it comprises iron, 10-14% निकल, और 16-18% क्रोमियम.
The real distinction in the stainless steel 316 बनाम 304 SS comparison is the presence of molybdenum (2-3%) alongside the other alloying elements such as carbon, मैंगनीज, और सिलिकॉन.
Physical and mechanical properties：
- Density: The density of 316 stainless steel is 8.0g/cm³.
- कठोरता: Typically measured by Brinell hardness, with a maximum hardness of about 215 HB for bar and section forms.
- गलनांक: लगभग 1400 को 1450 ° C (2552 को 2642 ° F)
- विशिष्ट गर्मी की क्षमता: आस-पास 484 J/kg·K at room temperature.
- Coefficient of thermal expansion: At 20℃, the coefficient of thermal expansion of 316 stainless steel is 16.5×10⁻⁶/℃, which means that for every 1℃ increase in temperature, the length of the material will increase by a corresponding proportion.
- Thermal conductivity: The thermal conductivity of 316 stainless steel is 16W/(m·K).
- Resistivity: The resistivity of 316 stainless steel is 7.2×10⁻⁷Ω·m.
- Tensile strength: Usually between 500 और 700 मेगापास्कल (एमपीए).
- Conditional Yield Strength (0.2% Proof Stress): Typically around 220 MPa for plate forms.
316 stainless steel has a wide range of applications, as follows:
- Marine Engineering: 316 stainless steel has excellent resistance to seawater corrosion, so it has been widely used in marine engineering fields such as ships, offshore platforms, and submarine pipelines.
- Chemical Production: It can resist the erosion of most harmful chemicals and is often used as a manufacturing material for equipment such as storage tanks and reactors.
- Pharmaceutical Manufacturing: It has little impact on drugs and is easy to clean and disinfect, so it is often used as a manufacturing material for pharmaceutical processing and storage equipment.
- Food Processing: As food-grade stainless steel, it is used to manufacture food processing equipment, मेज, kitchen utensils, and other utensils.
- Medical Equipment: It has good biocompatibility and corrosion resistance, and has been widely used in the manufacturing of medical equipment, such as artificial joints, dental instruments, surgical instruments, वगैरह.
- Architectural Decoration: It has a beautiful appearance, solid texture, and strong anti-fouling performance. It is often used as an interior decoration material in the field of architectural decoration.
- Petrochemical Industry: It is used for industrial pipelines such as petroleum, रासायनिक, चिकित्सा, खाना, light industry, and mechanical structural components.
इसके अलावा, 316 stainless steel is also used to make kitchen utensils such as knives, cutting boards, वगैरह।, as well as household facilities such as kitchen countertops, sinks, range hoods, वगैरह. due to its excellent corrosion resistance and high-temperature strength.
3. Key Differences Between 304 बनाम 316 स्टेनलेस स्टील
To effectively choose between 304 और 316 स्टेनलेस स्टील (एसएस), it’s essential to understand their key differences. Below are the distinctions that matter most:
रासायनिक रचना
304 एसएस: Composed of Carbon (0.07%), सिलिकॉन (1%), मैंगनीज (2%), फास्फोरस (0.045%), Sulphur (0.015%), नाइट्रोजन (0.10%), क्रोमियम (18%), और निकल (8%).
316 एसएस: Contains Carbon (0.07%), सिलिकॉन (1.00%), मैंगनीज (2.00%), फास्फोरस (0.045%), Sulphur (0.015%), नाइट्रोजन (0.10%), क्रोमियम (16%), निकल (10%), और मोलिब्डेनम (2.00%).
The primary distinction lies in the presence of molybdenum and the varying percentages of chromium and nickel, affecting their properties.
यांत्रिक विशेषताएं
- नम्य होने की क्षमता: Measures the maximum force a material can withstand before permanent deformation. 304 SS has a yield strength of 215 एमपीए, जबकि 316 SS has a yield strength of 205 एमपीए. This subtle difference is crucial for high-precision applications.
- कठोरता: Reflects a material’s resistance to deformation and indentation. 316 SS is harder, with a Rockwell B hardness of 79, compared to 304 SS at 70 Rockwell B. इस प्रकार, 316 SS is better suited for demanding projects that require higher hardness.
- लोच का मापांक: Indicates how a material resists deformation under stress. 304 SS has a higher modulus of elasticity (193-200 जीपीए) compared to 316 एसएस (164 जीपीए), making it more resilient to deformation.
संक्षारण प्रतिरोध
Both grades are corrosion-resistant, लेकिन 316 एसएस, thanks to its molybdenum content, excels in resisting corrosion, particularly in chloride and sulfuric acid environments.
Its enhanced corrosion resistance ensures easier cleaning without concerns over chemical compatibility.
गर्मी प्रतिरोध
- 304 एसएस: Performs well at high temperatures but may experience corrosion if continuously exposed to temperatures between 797-1580°F.
- 316 एसएस: Maintains functionality at temperatures exceeding 1550°F and below 850°F, making it more stable across a broader temperature range.
लागत
Due to its higher elemental content and added molybdenum, 316 SS is approximately 40% more expensive than 304 एसएस.
The increased corrosion resistance justifies the higher cost, निर्माण 316 SS a premium choice for specialized applications.
4. 304 बनाम 316 स्टेनलेस स्टील: Similarities
Despite their differences, 304 और 316 share several common traits that make them reliable choices for many applications.
चुंबकत्व
Both grades are non-magnetic in the annealed condition but may become slightly magnetic when cold-worked.
घर्षण प्रतिरोध
Both grades offer excellent abrasion resistance, making them suitable for environments where wear and tear are significant concerns.
जुड़ने की योग्यता
Both 304 और 316 stainless steel can be easily welded, although care must be taken to avoid post-weld corrosion in more demanding environments.
प्रपत्र
The formability of both grades is excellent, allowing them to be used in complex designs without cracking.
सहनशीलता
Both types offer long-term durability and resistance to environmental factors.
तन्यता ताकत
Both grades have excellent tensile strength, The SS 304 and SS 316 have a tensile strength of 500-700Mpa, making them suitable for working under the same conditions.
5. 304 बनाम 316 स्टेनलेस स्टील: How to Select the Right One?
Selecting the correct stainless steel grade depends primarily on the specific usage scenario and requirements. Each grade—304 and 316—has its unique advantages:
304 स्टेनलेस स्टील
- लाभ: Good general corrosion resistance and affordability.
- Usage: Suitable for resisting most everyday chemicals, including water, beverages, and food products.
- अनुप्रयोग: Commonly used in food processing equipment, kitchen utensils, and general household items.
- लागत: Relatively economical, making it a practical choice for standard applications.
316 स्टेनलेस स्टील
- लाभ: Enhanced corrosion resistance, particularly against chlorides, and higher durability.
- Usage: Ideal for harsh environments like marine settings or where contact with saltwater is common.
- अनुप्रयोग: Preferred for medical equipment, high-end kitchenware, and scenarios requiring superior material quality.
- लागत: More expensive than 304, reflecting its superior properties and longer lifespan.
सारांश, 304 stainless steel offers good corrosion resistance at a moderate price, making it ideal for everyday use.
316 स्टेनलेस स्टील, with its added molybdenum, provides exceptional resistance to chloride corrosion and is best for demanding environments and applications where durability is critical.
6. निष्कर्ष
Choosing between 304 और 316 stainless steel largely depends on the specific requirements of your project. While both alloys are durable and corrosion-resistant, 316 stands out in environments where chloride-induced corrosion is a concern.
Evaluate the environmental conditions, maintenance needs, and budget constraints to make the best selection for your application.
उपवास
क्यू: है 316 stainless steel stronger than 304?
ए: In terms of tensile strength, both are similar, लेकिन 316 exhibits better resistance to stress corrosion cracking.
क्यू: कर सकना 304 stainless steel be used in marine environments?
ए: जबकि 304 can be used in some marine applications, it is more susceptible to chloride-induced corrosion compared to 316.
क्यू: Can both 304 और 316 stainless steel be welded?
ए: हाँ, both can be easily welded, although care should be taken to avoid corrosion post-weld, particularly with 316 in harsh environments.
