Steel 7Cr17 (68Cr17) ​​High Carbon Stainless Steel

68Cr17 (7Cr17 steel)

68Cr17 (7Cr17 steel) is a Chinese martensitic stainless steel with high barbon and chromium content with higher quenching hardness than 2Cr13 steel. 7Cr17 stainless steel has high strength and hardness under quenching and tempering conditions, and has resistance to stainless steel and corrosion.

Note: 68Cr17 is the new designation for 7Cr17, that is, 68Cr17 = 7Cr17 steel.

7Cr17 steel is generally used to manufacture corrosion-resistant parts such as knives, gauges, shafts, valves and components that require corrosion and resistance to dilute oxidizing acids, organic acids and salts.

Technical sheet and specification

The following tables list the data sheet and specifications of 7Cr17 stainless steel, such as chemical composition, physical properties and mechanical properties, etc.

Chemical Composition of 7Cr17 Stainless Steel

The composition of 7Cr17 high carbon stainless steel is shown in the following table.

The values ​​in parentheses are the maximum values ​​that can be added or allowed.

Mechanical properties

For steel sheets and strips after annealing

• Extension strength: ≥245 MPa
• Tensile strength: ≥590 MPa
• Elongation: ≥15%
• HRC material hardness: ≤ 25
• HV hardness: ≤269
• Body weight: ≤255

For steel bar

• Hardness HRC :≥ 54 (Quenched and tempered);
• HBW Hardness : ≤ 255 (Annealing)

Physical properties

• Density (g/cm3): 7.78
• Melting point: 1371-1508°C
• Specific heat capacity (J/Kg·K): 160 at 0-100°C
• Thermal conductivity (W/m·K): 21.2 at 100°C
• Linear thermal expansion coefficients (10 ^-6 /K):
  • 10.2 (0-100°C)
  • 11.7 (0-500°C)
• Electrical Resistivity (μΩ·m): 0.6 at 20℃
• Longitudinal modulus of elasticity (kN/mm2): 200 to 20°C

Typical heat treatment specification

For steel bar

• Annealing: 800 – 920 ℃ (slow cooling)
• Quenching: 1010 – 1070 ℃ (oil cooling)
• Quenching: 100 – 180 ℃ (rapid cooling)

For steel sheets and strips

• Annealing: About 750°C (rapid cooling) or 800 – 900°C (slow cooling)
• Extinguishing: 1010 – 1070°C (rapid cooling)
• Quenching: 150 – 400 ℃ (air cooling)

Equivalence

68Cr17 (7Cr17 steel) equivalent to US ASTM AISI SAE, Japanese JIS standard for reference.