7Cr17 Steel (68Cr17) High Carbon Stainless Steel
68Cr17 (7Cr17 Steel)
68Cr17 (7Cr17 steel) is a Chinese high barbon chromium martensitic stainless steel with a higher quenching hardness than 2Cr13 steel. 7Cr17 stainless steel has high strength and hardness under quenching and tempering conditions, and has both stainless and corrosion resistance.
Note: 68Cr17 is the new designation of 7Cr17, in other words, 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.
Datasheet & Spacification
The following tables list the 7Cr17 stainless steel datasheet and specification such as chemical composition, physical properties and mechanical properties, etc.
7Cr17 Stainless Steel Chemical Composition
The composition of 7Cr17 high carbon stainless steel is displayed in the following table.
| Chemical Composition % | ||||||||
| Steel Grade | C | Si (≤) | Mn (≤) | P (≤) | S (≤) | Cr | Ni (≤) | Mo (≤) |
| 7Cr17 (68Cr17) | 0.60-0.75 | 1.00 | 1.00 | 0.040 | 0.030 | 16.00-18.00 | (0.60) | (0.75) |
The values in parentheses are the maximum values that can be added or allowed.
Mechanical Properties
For steel plate and strip after annealing
- Extension strength: ≥245 MPa
- Tensile strength: ≥590 MPa
- Elongation: ≥15%
- Material HRC hardness: ≤ 25
- HV Hardness: ≤269
- HBW: ≤255
For steel bar
- Material HRC Hardness:≥ 54 (Quenched and tempered);
- Material HBW Hardness: ≤ 255 (Annealing)
Physical Properties
- Density (g/cm3): 7.78
- Melting point: 1371-1508℃
- Specific heat capacity (J/Kg·K): 160 at 0-100℃
- Thermal conductivity (W/m·K): 21.2 at 100℃
- Coefficients of linear thermal expansion (10-6/K):
- 10.2 (0-100℃)
- 11.7 (0-500℃)
- Electrical Resistivity (μΩ·m): 0.6 at 20℃
- Longitudinal modulus of elasticity (kN/mm2): 200 at 20℃
Typical Heat Treatment Specification
For steel bar
- Annealing: 800 – 920 ℃ (Slow cooling)
- Quenching: 1010 – 1070 ℃ (Oil cooling)
- Tempering: 100 – 180 ℃ (Rapid cooling)
For steel plate and strip
- Annealing: About 750℃ (rapid cooling) or 800 – 900℃ (slow cooling)
- Quenching: 1010 – 1070℃ (rapid cooling)
- Tempering: 150 – 400 ℃ (Air cooling)
Equivalent Grade
68Cr17 (7Cr17 steel) equivalent to US ASTM AISI SAE, Japanese JIS standard for reference.
| 7Cr17 material equivalent | |||||||||||||
| China | US | Japan | German | France | UK | ISO | |||||||
| Standard | Grade | Standard | Grade (UNS) | Standard | Grade | Standard | Grade | Standard | Grade | Standard | Grade | Standard | Grade |
| GB/T 1220; GB/T 3280 | 7Cr17 | AISI, ASTM A276/A276M | 440A (S44002) | JIS G4303 | SUS 440A | ||||||||
