Editorial Feature

AISI 1020 Low Carbon/Low Tensile Steel

Image Credits: Sergey Ryzhov/shutterstock.com

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;

Element Content
Carbon, C 0.17 - 0.230 %
Iron, Fe 99.08 - 99.53 %
Manganese, Mn 0.30 - 0.60 %
Phosphorous, P ≤ 0.040 %
Sulfur, S ≤ 0.050 %

Physical Properties

The physical properties of AISI 1020 steel are;

Physical Properties Metric Imperial
Density 7.87 g/cc 0.284 lb/in³

Mechanical Properties

The mechanical properties of AISI 1020 steel are;

Mechanical Properties Metric Imperial
Hardness, Brinell 111 111
Hardness, Knoop (Converted from Brinell hardness) 129 129
Hardness, Rockwell B(Converted from Brinell hardness) 64 64
Hardness, Vickers (Converted from Brinell hardness) 115 115
Tensile Strength, Ultimate 394.72 MPa 57249 psi
Tensile Strength, Yield 294.74 MPa 42748 psi
Elongation at Break (in 50 mm) 36.5 % 36.5 %
Reduction of Area 66.0 % 66.0 %
Modulus of Elasticity (Typical for steel) 200 GPa 29000 ksi
Bulk Modulus (Typical for steel) 140 GPa 20300 ksi
Poissons Ratio 0.290 0.290
Charpy Impact
@Temperature -30.0 °C/-22.0 °F 16.9 J 12.5 ft-lb
@Temperature -18.0 °C/-0.400 °F 18.0 J 13.3 ft-lb
@Temperature -3.00 °C/26.6 °F 20.0 J 14.8 ft-lb
@Temperature 10.0 °C/50.0 °F 24.0 J 17.7 ft-lb
@Temperature 38.0 °C/100 °F 41.0 J 30.2 ft-lb
@Temperature 65.0 °C/149 °F 54.0 J 39.8 ft-lb
@Temperature 95.0 °C/203 °F 61.0 J 45.0 ft-lb
@Temperature 150 °C/302 °F 68.0 J 50.2 ft-lb
Izod Impact 125 J 92.2 ft-lb
Shear Modulus (Typical for steel) 80.0 GPa 11600 ksi

Machining

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.

Article Updated on 31st July, 2019

Comments

  1. Yousif Drizzy Yousif Drizzy Canada says:

    My question is, is it easier or more difficult to form martensite in a 1020 steel than in a eutectoid steel?

    • Andy Saputra Andy Saputra Indonesia says:

      u need to analyze both of the isothermal diagram of the eutectoid steel to this one.

  2. Pintu Chaurasiya Pintu Chaurasiya India says:

    my question is which one is best for gears of baja car either 1020 or en 353 ?

    • Heubach Mahendra Heubach Mahendra India says:

      AISI 1017
      AISI 1018
      AISI 4130

  3. Saima Muneer Saima Muneer Islamic Republic of Pakistan says:

    what is the austenitizing temperature of 1020 steel and what type of micro structural changes take place during heat treatment and austenitization.

  4. Saima Muneer Saima Muneer Islamic Republic of Pakistan says:

    thank you

  5. vinay kumar vinay kumar India says:

    I Would like to make a Go Kart .which is the best material in high strength in mediam costand light in weight

  6. NASHORNS PCCOER NASHORNS PCCOER India says:

    BEST SUITABLE MATERIAL FOR BAJA CHASSIS MANUFACTURING. MAIN FOCUS ON COST, WEIGHT, STRENGTH

  7. Hari Mohan Varshney Hari Mohan Varshney India says:

    Can we use Mild steel pipes for 25 m height monopole tower. The temperature range is (-40 to 40 deg). If yes please mention the grade also.

  8. suresh kumar suresh kumar India says:

    SAE1020 grade CD (Cold drawn) Not available in Indian market.so we have planned SAE1018 material.is it equivalent of SAE1020?

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of AZoM.com.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Submit