AISI 1040 Carbon Steel

Chemical Analysis
C Carbon
0.37 – 0.44
Mn Manganese
0.60 – 0.90 max
P Phosphorus
0.040 max
S Sulfur
0.050 max

General characteristics of Carbon Steel 1040

C1040 is a medium carbon, medium tensile steel supplied as forged or normalized.

Applications

This grade of steel is used for forged parts where the strength and toughness of the material are appropriate. C1040 may be used for the manufacture of forged crankshafts and couplings, along with a range of parts where the properties of heat-treated C1040 are suited to the application.

Forging

C1040 is forged from 2200ºF (1205ºC) down to a temperature in the region of 1650ºF (900ºC) The actual forging and finishing temperatures will depend on a number of factors, including overall reduction during forging and complexity of part being forged.
Experience alone will determine near exact values for these two parameters.
Parts are air cooled after forging.

Heat treatment

Annealing

Full annealing of small C1040 forgings is carried out from 1450-1600ºF (840-890ºC)

followed by furnace cooling at 50ºF (28ºC) per hour, to 1200ºF (650ºC) soaking and air cooling.

Normalizing

The normalizing temperature range for this grade is typically 1600-1650ºF (870-900ºC)
Normalizing is followed by cooling in still air. When forgings are normalized before hardening and tempering or other heat treatment, the upper range of the normalizing temperature is used. When normalizing is the final treatment, the lower temperature range is used.

Hardening

Hardening of this grade is carried out from an austenitizing temperature of 1525-1575ºF (830-860ºC) followed by oil or water quenching.

Flame and induction hardening may be carried out by heating quickly to the desired case depth and quenching in water or oil. This should be followed by a tempering treatment at 300-400ºF (150-200ºC) to reduce stresses in the case without affecting its hardness. A hardness of Rc 50-55 may be obtained by surface hardening.

Tempering

Tempering after normal hardening and oil or water quenching is carried out at 750-1260 ºF (400-680ºC) to give the required mechanical properties as determined by practical experience.

Machinability

Machinability of C1040 is good providing the full annealing cycle described above is used, ensuring a coarse lamellar pearlite to coarse spheroidite microstructure.

Weldability

This grade is readily welded with the correct procedure. Welding in the through-hardened or flame or induction-hardened conditions is not recommended.

Low-hydrogen electrodes are recommended together with preheat at 300-500ºF (150-260 ºC.) to be maintained during welding, Cool slowly and stress relieve where possible.

To Send a Request for Quote, please Click Here, or call 1.973.276.5000 or 1.800.600.9290 or fax 1.973.276.5050.