Basic knowledge

A106b cold drawn round steel is a high quality low carbon carbon steel, cold extruded, carburized and hardened steel.

Cold drawn round steel is extremely versatile, and round steel is often used for machining raw materials and processing into mechanical parts and accessories.

Chemical composition (% by mass)

C0.17-0.25, Si0.17-0.37, Mn0.35-0.65, P≤0.035, S≤0.035, Ni≤0.30, Cr≤0.15, Cu≤0.25

Supply status and hardness

Bright surface, hardness ≤ 156HBS

characteristic

The steel has low strength and good toughness, plasticity and weldability. The tensile strength is 355-500 MPa and the elongation is ≥24%.

Normalizing can promote the spheroidization of the steel, refine the large block of pro-eutectoid ferrite, and improve the cutting performance of less than 160HBS blanks.

Processing technology and specifications

Routing

Blanking - Forging Die - Annealing - Mechanical Roughing - Cold Extrusion - Recrystallization Annealing - Mechanical Finishing - Carburizing - Quenching, Tempering - Grinding - Assembly.

Process specification

Normalizing specification: The temperature is 920-950 °C, and the air is cooled. Hardness 131-156HBS.

Cold-pressed embryo softening treatment specification: temperature 700~720°C, holding time 8~15h, with a cooling rate of 50~100°C/h, with the furnace falling to temperature ≤550~600°C, air cooling. The hardness before treatment is ≤143HBS, and the hardness after treatment is ≤131HBS.

Quenching specification: temperature 910 ° C ± 10 ° C, 10% NaCl brine cooling.

Typical application example

1. Serrated lock washer die: This cold die is used for stamping 65Mn steel strip with hardness of 179-217HBS. It is originally made of T10 steel, hardness 48-50HRC, service life is less than 1500 times; later adopts Cr12MoV steel, hardness 48-50HRC, The service life is less than 3000 times; after the 20th steel which is directly used after quenching without tempering, the hardness is 46-48HRC, and the service life is up to 3-4 million times;

2, cold extrusion punch, heavy duty cold head punch, 10-25mm medium thick steel plate punching punch, small punch with diameter less than Φ6mm, can be used for small and medium austenitic steel, spring steel, high strength steel plate shower.

3, small high-life cold punching and shearing tools.

4. Powder metallurgy stamping.