Introduction to 316 Round Bars
The stainless steel bars market is immense and there is a rising demand for these bars. One such stainless steel bar that surpasses its other counterparts is grade 316 round bars. They are used in various applications across industries because of their high corrosion resistance and mechanical properties, even in extreme conditions.
Let’s keep reading to explore more about 316 round bars.
Overview of 316 Stainless Steel
The 316 grade is an austenitic stainless steel type. It shows high corrosion resistance to even extreme conditions, owing to its chemical composition that comprises 16-18% chromium, 10-14% nickel, and 2-3% molybdenum.
It is also known as “marine grade stainless steel” because it shows good corrosion resistance to saltwater.
Common Applications of 316 Round Bars
316 round bars find their application in various industries. Due to its strength and corrosion resistance, along with excellent heat-treating capabilities, it can be adopted in multiple applications such as:
- Marine Conditions: It is widely used in fittings for boats and underwater equipment.
- Chemical Process: Various equipment for chemical industries that have to endure harsh chemicals.
- Medical and Pharmaceutical Industries: Used in surgical and pharmaceutical-related equipment.
- Food and Beverage: Sanitary process-related equipment.
Properties of 316 Round Bars
Below, we have some critical properties of 316 round bars, which are very crucial while considering them for your application:
Mechanical Properties
- Tensile Strength (min): 515 MPa
- Yield Strength (min): 205 MPa
- Elongation (min): 40%
- Hardness: Rockwell B max 95, Brinell max 217
These properties ensure that 316 round bars can withstand high stress and load, making them suitable for heavy-duty usage.
Corrosion Resistance
316 round bars have high corrosion resistance, particularly in environments with chlorides, acids, and other corrosive agents. In warm chloride medium such as seawater, it may show signs of slight pitting and crevice corrosion. Overall, grade 316 is generally more resistant than 304 stainless steel for general-purpose use in severe conditions.
Heat Resistance
316 stainless steel has good oxidation resistance in intermittent service up to 870°C and in continuous service up to 925°C. For high-temperature applications, the higher carbon content variant, 316H, can be used as it has greater strength at elevated temperatures.
Manufacturing Process of 316 Round Bars
The manufacturing process of 316 round bars includes many key steps, so that the material is able to achieve its full potential, including strength, durability, and resistance to corrosion. This starts from selecting proper raw materials and followed by other steps.
Raw Material Selection
High-grade raw material is used for the manufacturing of 316 round bars. It primarily constitutes iron, chromium, nickel, and molybdenum. Raw materials have to be of high quality in order to meet the mechanical and corrosion-resistant requirements of these bars.
Hot and Cold Working Techniques
- Hot Working: Raw materials are melted and cast in the form of billets, then hot rolled into bar shapes in crude form. Hot working allows the shaping of the raw material at very high temperatures.
- Cold Drawing: Cold drawing is performed after hot rolling on bars to provide a fine level shape and improved surface finish. The yield strengths and tolerance of the bars are improved in this process.
Heat Treatment and Annealing
- Solution Annealing: Bars are subjected to high temperatures typically around 1040-1175°C for solution annealing. It dissolves the carbides and promotes corrosion resistance.
- Stress Relief Annealing: Bars are heated to a lower temperature and cooled slowly to decrease stresses developed during hot working.
Dimensions and Specifications
Standard Sizes of 316 Round Bars
They are available in standard sizes, generally between 8mm to 75 mm in diameter. The standard length varies between 2 mts to 6 mts.
Tolerances and Finishing Options
- Tolerance: Available in several tolerances: f7,f8,h7 and h8.
- Finishing: Centreless Ground & Belt Polished up to Ra value 0.2 microns (12 RMS) and 24-320 Grit Polished
Custom Sizes and Fabrication Services
They are also available in custom sizes and fabrication services to meet unique industrial needs like cutting, threading, or further machining.
Advantages of Using 316 Round Bars
- Durability and Longevity: 316 round bars are extremely tough and offer excellent resistance to wear and tear, corrosion, and high temperatures. This makes them cost-effective in the long run, even though they are relatively more expensive initially compared to other steel rods.
- Versatility in Various Industries: From maritime equipment to chemical processing plants, 316 round bars are versatile enough to cater to almost all application requirements.
- Cost-Effectiveness Over Time: Although 316 stainless steel is costlier owing to its high-end chemical composition, but being a very resilient material that lasts longer and has low maintenance, making it quite effective in the long run.
Applications of 316 Round Bars
- Marine Industry: 316 round bars are used for fitting boats, underwater pipelines, etc., as they show high corrosion resistant in saltwater environments.
- Chemical Processing: In chemical plants, being highly corrosion-resistant to chemicals, 316 round bars are used to make equipment exposed to corrosive chemicals.
- Medical and Pharmaceutical Uses: Hygienic properties and corrosion resistance make 316 stainless steel ideal for medical devices, surgical instruments, and any pharmaceutical-related equipment.
Comparison with Other Stainless Steel Grades
316 vs. 316L vs. 304
- There is a lesser percentage of carbon in 316L than in 316. It yields better resistance against carbide precipitation that often results from welding operations.
- 304 stainless steel is more corrosion-prone than 316, especially in chloride environments, but cheaper for general-purpose applications.
Suitability for Different Environments
316 stainless bars are typically used in aggressive or corrosive environments, whereas 304 are more suitable for general uses. 316L is best for weld-bonded structures that demand high corrosion resistance.
Storage and Handling Recommendations
- Best Practices for Storage: 316 round bars have to be stored in clean and dry conditions so to avoid any unnecessary corrosion.
- Safety Considerations During Handling: During handling, the lift on the lifter should be proper, and safety accessories such as gloves and protective footwear should be worn when handling these heavy bars so that injuries are avoided.
Future Trends in 316 Round Bar Applications
The advancing manufacturing techniques and augmenting demands in industries like marine, medical, and chemical processing will further increase their demand in applications where high performance and durability are of prime concern. If you are looking for the right 316 round bar for your application, contact Ambica Steels.
FAQs About 316 Round Bars
Q1: What is the difference between 316 and 316L stainless steel?
A: 316L contains less carbon and it resists carbide precipitation in welding better than the regular 316.
Q2: Are 316 round bars suitable for use in marine environments?
A: Yes, they are widely used in marine systems due to their high corrosion-resistance to saline water. However, they are not ideally suited for chloride environments as 316 stainless steel shows surface corrosion to chloride environments.
Q3: What is the conventional size set for 316 round bars?
A: They are available in standard sizes, generally between 8mm to 75 mm in diameter. The standard length varies between 2 mts to 6 mts.
Q4: How does molybdenum in 316 round bars improve their performance?
A: Molybdenum adds corrosion resistance to 316 stainless steel, making it usable in harsh environments compared to 304 stainless steel.
Q5: Are 316 round bars used at high temperatures?
A: Yes, 316 round bars have good heat resistance. They can be used in the intermittent service up to 870°C and in continuous service up to 925°C. However, for higher temperature strength than above, 316H is preferred.
