AISI 1020 Carbon Steel Channel Low hardenability properties

AISI 1020 has low hardenability properties and is a low tensile carbon steel with a Brinell hardness of 119 – 235, and a tensile strength of 410-790 MPa. It has high machinability, high strength, high ductility and good weldability. It is normally used in turned and polished or a cold drawn condition. Due to its low carbon content, it is resistant to induction hardening or flame hardening. Due to lack of alloying elements, it will not respond to nitriding. However, carburization is possible in order to obtain case hardness more than Rc65 for smaller sections that reduces with an increase in section size. The core strength will remain the same. Alternatively, carbon nitriding can be performed, offering certain benefits over standard carburizing.

AISI 1020 steel can be largely utilized in all industrial sectors in order to enhance weldability or machinability properties. It is used in a variety of applications due to its cold drawn or turned and polished finish property.

Chemical Composition

The chemical composition of AISI 1020 steel is;

Physical Properties

The physical properties of AISI 1020 steel are;

Mechanical Properties

The mechanical properties of AISI 1020 steel are;

In the cold drawn or turned and polished condition, AISI 1020 steel has high machinability. Following the recommendations of machine manufacturers, AISI 1020 steel can be used for drilling, turning, milling and tapping operations using suitable feeds, tool type and speeds.

Weldability

AISI 1020 can be welded by performing the most common welding processes. In the cold drawn or turned and polished condition, it has better weldability. It has been suggested that the welding process should not be performed in heat treated or carburized condition.

Heat Treatment

Annealing

AISI 1020 steel is heated at 870°C - 910°C followed by a period of holding for a specific amount of time, until the temperature remains constant all over the section. It is then cooled in a furnace.

Carburizing

AISI 1020 is heated to between 880°C - 920°C in a suitable carburizing atmosphere followed by holding for a sufficient amount of time to produce the required carbon content and case depth. After this, refining/hardening and tempering processes are carried out to optimize the core and case properties.

Core Refining

AISI 1020 steel is slowly cooled and re-heated at 870°C - 900°C followed by a period of holding until the temperature remains constant all over the section and is quenched in water, oil or brine.

Case Hardening

After performing the core refining process, it is re-heated to 760°C - 780°C followed by a period of holding until the temperature is consistent all over the section. It is then quenched in water.

Tempering

AISI 1020 steel is re-heated at 150°C - 200°C followed by a period of holding for a certain time until the temperature remains constant throughout the section. It is soaked for 1 hour per 25 mm of section, and then cooled under normal atmosphere. By performing the tempering process, the toughness of the case will be improved and grinding cracks will be reduced.

Normalizing

AISI 1020 steel is heated at 890°C - 940°C followed by a period of holding until the temperature remains constant throughout the section. It is soaked for 10 - 15 minutes and then cooled in still air.

Stress Relieving

AISI 1020 steel is heated to 650°C - 700°C followed by holding until the temperature remains constant all over the section and soaking for 1 hour per 25 mm of section. It is then cooled in still air.

Applications

AISI 1020 steel is used in case hardened condition and used for simple structural applications such as cold headed bolts.

AISI 1020 steel is also used to manufacture axles, general engineering and machinery parts and components, shafts and camshafts, gudgon pins, ratchets, light duty gears and spindles.