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Stainless Steel 303
Stainless steel 303 is known for its excellent machinability, good corrosion resistance, and remarkable toughness, ideal for CNC machining.
Chemical Composition of Stainless Steel 303
Stainless Steel 303 is characterized by its unique chemical composition, which imparts specific properties to the alloy. Here is a detailed breakdown of its chemical composition, presented in a tabular format:
| Chemical Composition | Proportions | Role of Each Element |
|---|---|---|
| Chromium (Cr) | 17.0% - 19.0% | Chromium is essential for stainless steel's corrosion resistance. It forms a passive layer that protects the steel from oxidation and rust. |
| Nickel (Ni) | 8.0% - 10.0% | Nickel enhances corrosion resistance and toughness. It also improves the steel's formability and strength, particularly at low temperatures. |
| Manganese (Mn) | Up to 2.0% | Manganese aids in the steel's hot working process and enhances its strength and hardness. It also acts as a deoxidizer. |
| Carbon (C) | 0.15% Maximum | Carbon increases the hardness and strength of the steel but in higher amounts can reduce its corrosion resistance. 303 maintains a low carbon level to balance these effects. |
| Silicon (Si) | Up to 1.0% | Silicon is used primarily as a deoxidizer in steel manufacturing and can slightly improve corrosion resistance. |
| Phosphorus (P) | Up to 0.20% | Phosphorus is added to improve the strength and machinability of the steel, but high levels can reduce its toughness. |
| Sulfur (S) | 0.15% - 0.35% | Sulfur is added to enhance machinability, a key characteristic of 303. However, it can slightly reduce the corrosion resistance and weldability. |
| Molybdenum (Mo) | Up to 0.60% | Molybdenum can be added to improve corrosion resistance, particularly in more acidic environments. |
| Iron (Fe) | Balance | Iron is the base element of stainless steel, comprising the bulk of the alloy. |
This composition makes Stainless Steel 303 highly machinable and suitable for applications requiring precision, such as those produced using CNC machining. The combination of elements provides a balance between machinability, corrosion resistance, and mechanical properties.
General Characteristics of Stainless Steel 303
Stainless Steel 303 offers excellent machinability, good corrosion resistance, and non-magnetic properties with decent toughness and ductility.
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Physical properties
| Density | 7.8 to 8.03 g/cm3 |
| Corrosion resistance | Moderate |
| Melting Point | 1,400°C to 1,425°C |
| Magnetism | Non-magnetic |
| Coefficient of Thermal Expansion | 17.3 to 17.8 x 10^-6 /°C |
| Thermal Conductivity | 16.3 W/m·K |
| Electrical properties | Approximately 72 microohm-centimeters (µΩ·cm) at 20°C |
Mechanical properties
| Ultimate Tensile Strength (UTS) | 500 to 750 MPa |
| Yield Strength (0.2% Offset) | 190 to 240 MPa |
| Elongation at Break | 35% to 55% |
| Modulus of Elasticity (Elastic Modulus) | Approximately 193 GPa |
| Fatigue Strength | 240 to 260 MPa |
| Brinell Hardness | Approximately 202 HB |
| Vickers Hardness | Typically around 230 HV |
Available Surface Finishing
| Passivation | Enhances corrosion resistance by removing free iron with acid, forming a protective oxide layer. |
| Bead Blasting | Propels fine beads at high pressure, creating a uniform matte finish, reduces glare. |
| Polishing | Utilizes abrasives for a smooth, shiny finish, enhances appearance, and increases surface cleanliness and corrosion resistance. |
| Brushed or Satin Finish | Abrasive polishing for a brushed look, hides fingerprints and minor scratches, offers aesthetic appeal. |
Note: The properties of Stainless Steel 303 can exhibit minor variations depending on the supplier.
Types of CNC Machining Stainless Steel Process
AT-Machining employs various stainless steel machining services to produce high-quality components in diverse shapes and sizes. Our capabilities include CNC milling, turning, Swiss machining, EDM, and grinding.
By combining these techniques, our skilled engineers craft efficient manufacturing solutions tailored to each project’s specifications.
With a focus on precision and accuracy from start to finish, AT-Machining consistently meets both our own rigorous standards and our customers’ expectations.
Common Applications of Stainless Steel 303
CNC machining of Stainless Steel 303 is widely used for precision components in aerospace, medical, automotive, and industrial sectors due to its machinability and durability.
Aerospace
Stainless Steel 303 is essential for producing high-precision aerospace components like bushings, gears, and fasteners. Demands exact tolerances, high reliability, and performance under various stress conditions and temperatures.
Medical Devices
In medical applications, Stainless Steel 303 is used for surgical instruments, implants, and equipment parts requiring precise manufacturing. Offers corrosion resistance, non-magnetic properties, and safety in medical environments.
Industrial Automation
The automation and robotics sector uses Stainless Steel 303 for parts in machinery and robotic systems. It ensures high accuracy, repeatability, and durability in automated processes and corrosive environments.
FAQS About Stainless Steel 303
Yes, Stainless Steel 303 can be welded, but it requires careful consideration due to its sulfur content which can cause hot cracking. The sulfur that makes 303 so machinable also lowers its weldability compared to other austenitic stainless steels like 304.
It can withstand moderate high temperatures but may not be suitable for extreme high-temperature environments compared to some high-performance alloys.
Optimal speeds and feeds, using sharp tools, and appropriate coolant use are key for quality machining and tool longevity.
While it’s generally safe, Stainless Steel 304 is often preferred for food-grade applications due to better corrosion resistance.
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