1045 Carbon Tool Steel - DIN 1.1730 - C45U - SAE 1045

As a versatile, carbon-based cold work steel, 1045 has good strength and impact properties, as well as good machinability and reasonable weldability. It is a case-hardening steel with a shallow depth of hardening with a hard surface and a tough core. It is used by many industry sectors for its good mechanical strength and good machinability and is mainly used in its as-delivered condition. 1045 has better mechanical properties as well as higher wear resistance than 1018/A36. Due to the lack of suitable alloying elements, this steel does not lend itself to the nitriding process, but can be hardened by flame or induction hardening.

Applications

Applications for this tool steel include: chisels, punch holders, guide plates, backing plates, simple bending dies, simple structural components, top and bottom die casting, tongs, leather knives, forged connecting rods, torsion bars and fixtures.

Heat treatment

Annealing

Protect the steel and heat the work piece uniformly to 1290°F (700°C). Following this cool the parts down to 1110°F (600°C) in the furnace at a rate of 78°F (25°C) per hour, then continue to cool further in air.

Normalizing

Heat the material to 1545-1066°F (840-870°C) until it is heated through evenly. Then allow parts to cool further in air.

Stress relieving

Heat the work piece to a temperature of 1200°F (650°C), hold for 2 hours, when the entire piece is heated through to temperature. Then bring the temperature of the work piece down to 930°F (500°C) in the furnace and continue to cool it further in air.

Hardening

Preheat the work piece to 1200°F (650°C).

Austenitizing temperature: 1510-1600°F (820-870°C), soak parts for a minimum of 1 hour or for 10-15 minutes per inch (25.4 mm) of thickness and protect against decarburization. Quench in water or brine.

Flame and induction hardening can be accomplished by rapidly heating the material to the desired case depth followed by quenching in oil or water. This is followed up with a temper at 300-400°F (150-200°C) to reduce stresses but without affecting the hardness.

Quenching media

• Water
• Oil
• Brine

Tempering

To temper 1045 after hardening or oil and water quenching, heat the material to a temperature range of 750-1260°F (400-680°C) for 1 hour per inch (25.4 mm), then cool in still air.

For our tempering diagram, please click here.

Machinability

1045 has good machinability and can be used for tapping, drilling, milling, turning and broaching provided this is executed adequately, applying sufficient feeds, speeds and tools.

Forging

Preheat parts to 1382-1472°F (750-800°C), then increase the temperature to 2012-2192°F (1100-1200°C) and hold at this temperature until the material is uniformly heated through. Forge the work piece immediately and finish with a furnace cooling. Do not continue forging below 1562°F (850°C).

Welding

Weld 1045 can be done by all conventional welding processes, assuming all the correct processes are used. To avoid cracking, pre- and post-heating is required. Preheat at 210-660°F (100-350°C) and maintain this temperature during welding. When finished, cool slowly in sand or ash and relieve stress at 1022-1220°F (550-660°C). Welding 1045 is preferably carried out using low hydrogen electrodes.