1.2631, X50CrMoW9-1-1 - tool steel

1.2631, X50CrMoW9-1-1 - hardenable tool steel

1.2631, X50CrMoW9-1-1 – description

1.2631 is a medium alloyed Cr-Mo-W hardenable cold work tool steel. It is tough, wear and shear resistant. It is shipped in annealed condition.

Applications

The steel is used for severly stressed wood cutting knives, flat and round shear knives, mainly in the papaer, fiberboard and cellulose industries.

1.2631, X50CrMoW9-1-1- physical and mechanical properties

Room temperature physical properties for Bohler K350 steel according to the manufacturer:

• Density: 7.7 g/cm³
• Specific heat capacity: 460 J/kg⋅K
• Thermal conductivity: 26 W/m⋅K
• Young's Modulus: 210 GPa

Coefficient of Linear Thermal Expansion for Sihard 2631 steel according to the SIJ Metal Ravne:

• 26-100°C: 9.8 *10^-6m/(m*K)
• 26-200°C: 10.2 *10^-6m/(m*K)
• 26-300°C: 10.5 *10^-6m/(m*K)
• 26-400°C: 11.3 *10^-6m/(m*K)
• 26-500°C: 11.9 *10^-6m/(m*K)
• 26-600°C: 12.4 *10^-6m/(m*K)
• 26-700°C: 12.8 *10^-6m/(m*K)
• 26-800°C: 13.0 *10^-6m/(m*K)

Hardness HRC for hardened Sihard 2631 steel as a function of the subsequent tempering temperature:

• No tempering: 61 HRC
• 100°C: 60 HRC
• 200°C: 57 HRC
• 300°C: 56 HRC
• 400°C: 56 HRC
• 500°C: 59 HRC
• 525°C: 59 HRC
• 550°C: 53 HRC
• 575°C: 48 HRC
• 600°C: 43 HRC
• 700°C: 33 HRC

Hardness of 1.2631 steel in softened annealed condition, before hardening: <228 HB.

Heat treatment, working and machining

Typical heat treatment parameters:

• Forging: 1050-900°C
• Soft annealing: 820-870°C; Furnace cooling
• Stress relieving: 650°C; 1h; air cooling
• Hardening: 1020-1050°C, followed by quenching in oil, air or hot water at 400°C
• Tempering: 150-400°C, depending on target hardness (see section "physical and mechanical properties")

We deliver this steel alloy as:

• Bars
• Forgings
• Sheets

Replacements, equivalents and other designations:

1.2631, X50CrMoW9-1-1, Bohler K350, Sihard 2631, WR Spezial, CRV23, Ch.4755, BSC 3