AISI 4130 steel is a low alloy steel that is used in structural designs that may be found in applications such as aircraft engine mounts or welded tubing. It is well known for its ease of welding and ability to harden in commercial applications. It is commonly referred to as chromium-molybdenum steel.
AISI 4130 steel is comprised of seven different elements. The weight of each of these elements is measured as a percentage and must stay within the designated range to meet steel standards. The composition must be between 0.28 and 0.33 percent carbon and 0.4 to 0.6 percent manganese. The amount of phosphorous and sulfur must be less than 0.035 and 0.04 percent respectively. The amount of silicon must range between 0.15 and 0.30 percent. Chromium ranges between 0.8 and 1.10 percent while molybdenum must measure between 0.15 and 0.25 percent.
The mechanical specifications of AISI 4130 steel are standard at 25 degrees Celsius. The density of the material must be between 7700 and 8030 kg per cubic meter while the Poisson ratio must be between 0.27 and 0.30. The elastic modulus ranges between 190 and 210 while the tensile strength and yield strength are 560.5 and 360.6 respectively. Elongation is 28.2 percent and the reduction in area is 55.6 percent. Hardness is rated at 156 and the impact strength is 61.7.
Thermal and Electric Specifications
AISI 4130 is a thermal conductor capable of a rating of 42.7 measured at 100 degrees Celsius. The specific heat it can handle is 477 at 50 to 100 degrees Celsius. The electric resistivity has been measured at 223 when tested at 20 degrees Celsius.
AISI 4130 can be heated as a way to harden the material. When hardening is desired, the material should be heated at a minimum of 1600 degrees F. followed by an oil quench. The best results can be obtained when heating occurs between 1650 and 1700 degrees, followed by an oil quench and soak of 1600 degrees. If the material loses too much ductility during this process, the material can be tempered to restore some of the function. Tempering should be conducted at temperatures between 750 and 1050 degrees, depending on the resultant strength desired. The lower temperatures generally result in greater strengths during the tempering process. Heating can also be used to make the material easier to work with. Manipulation heating can be best conducted in a range of 2000 to 1500 degrees.