Description
C55MN75 Grade Introduction:
C55MN75 is a carbon steel that falls within the medium to high-carbon category. Carbon is the primary alloying element, with small amounts of silicon and manganese also present. This grade features excellent wear resistance and strength, making it ideal for heavy-duty applications. Additional trace elements like molybdenum, copper, nickel, and chromium may also be present in small amounts, contributing to enhanced mechanical properties.
C55MN75 Grade Applications:
Due to its toughness and resistance to wear, C55MN75 is commonly used in:
- Agricultural Implements
- Heavy Machinery Components
- Wear-Resistant Parts
- Ring-Rolling Tools
- Battering Tools
- Hand Tools
- Springs
C55MN75 Equivalent Grades:
C55MN75 shares similarities with several other steel grades, including:
- C45, C50, CK45
- EN8, EN9, EN24, EN31
- SAE52100, 42CrMo4
- S40C, S355J2G3
Additional Grades:
Other related grades supplied alongside C55MN75 include:
- MS, EN1A, EN3B, EN8D, EN36C
- P20, P20+Ni, P20+S
- H11, H13, D2, D3
- SCM420, ASTM SA-36, ASTM SA-105
C55MN75 Chemical Composition:
The chemical composition of C55MN75 primarily includes:
- Carbon (C): 0.50-0.60%
- Manganese (Mn): 0.60-0.90%
- Silicon (Si): 0.15-0.35%
C55MN75 Mechanical Properties:
C55MN75 exhibits excellent mechanical strength and toughness, making it ideal for wear-resistant applications:
- Tensile Strength (Ultimate): 660 MPa (95,700 psi)
- Tensile Strength (Yield): 560 MPa (81,200 psi)
- Elongation at Break: 10%
- Reduction of Area: 40%
- Hardness (Brinell): 197 HB
C55MN75 Hardness:
- The hardness of C55MN75 typically falls at 197 HB on the Brinell scale, with approximate conversions to other hardness tests:
- Knoop: 219
- Rockwell B: 92
- Rockwell C: 13 (below typical HRC range)
- Vickers: 207
C55MN75 Heat Treatment:
C55MN75 can undergo various heat treatment processes to improve its mechanical properties:
- Normalizing: Performed at temperatures ranging from 1550°F to 1625°F (843°C to 885°C).
- Annealing: Full annealing is done at 1525°F to 1600°F (829°C to 871°C), followed by furnace cooling, while process annealing is performed at 1100°F to 1225°F (593°C to 663°C) after cold working.
C55MN75 Hardening:
Due to its carbon content, C55MN75 can be hardened through quenching and tempering processes, which improve its wear resistance and toughness.
C55MN75 Tempering:
After hardening, C55MN75 is tempered to adjust hardness and ductility. The exact tempering temperature will depend on the desired properties of the final component.
C55MN75 Physical Properties:
- Density: 7.85 g/cm³ (0.284 lb/in³)
- Modulus of Elasticity: 190-210 GPa (29,700-30,458 ksi)
- Bulk Modulus: 140 GPa (20,300 ksi)
- Shear Modulus: 80 GPa (11,600 ksi)
- Poisson’s Ratio: 0.27-0.30
C55MN75 Thermal Properties:
C55MN75 steel demonstrates good thermal properties, making it suitable for applications involving high temperatures.
C55MN75 Forging Properties:
Forging of C55MN75 is carried out at temperatures between 900°C and 1200°C. Post-forging, it can be air-cooled or furnace-cooled depending on the desired properties.
C55MN75 Stress Relieving:
Stress relieving is performed to reduce internal stresses that accumulate during machining or heat treatment processes. This is done at lower temperatures, typically around 600°C.
C55MN75 Machinability:
C55MN75 can be machined using high-speed steel cutters with sulfured or chlorinated cutting oils, or carbide-tipped tools. Below are suggested machining angles:
- Side Rake: 8-12°
- Back Rake: 6-10°
- Side Relief: 7-9°
- End Relief: 7-9°
- Side Cutting-Edge Angle: 12-16°
- End Cutting-Edge Angle: 8-14°
- Nose Radius: 10% of the cut depth
For carbide-tip tools:
- Side Rake: 6-12°
- Back Rake: 2-8°
- Side Relief: 6-10°
- End Cutting-Edge Angle: 8-12°
- Side Cutting-Edge Angle: 8-16°
- Nose Radius: 1/32”
C55MN75 Welding:
C55MN75 can be welded using appropriate methods depending on its condition and application. Preheating may be required to prevent cracking, and post-weld heat treatment is recommended to relieve stresses.
This detailed overview provides a comprehensive look into the characteristics and applications of C55MN75 grade steel.
