Hello!
I’m thinking of making a flat spring myself with a piece of material sus440c that I have. Can it be made into a spring if it is cut to the length of 30 mm, the width of 3 mm, the thickness of about 2 mm and subjected to appropriate heat treatment? If it is possible, it would be appreciated it if you could tell me the appropriate heat treatment temperature.
Thank you.
Spring Newbie, thank you for your question!
I think that SUS440C can be used as flat spring material ♪
JIS G4305 also describes the conditions for SUS440A. Since SUS440C is martensitic stainless steel, quenching and tempering are generally used for heat treatment.
Quenching: 1010℃ to 1070℃ Rapid cooling
Tempering: 150℃ to 400℃ Air cooling
The final hardness (material strength) varies depending on the quenching and tempering temperature, so please consider and set the load stress carefully when using it as material for flat springs.
In quenching, the material gets harder as the temperature gets closer to 1070℃. With tempering, the hardness increases as the temperature approaches 150°C.
Reference: In the case of quenching at approximately 1050°C and tempering at approximately 200°C, the final hardness is around HRC60.
* It also depends on the heat treatment equipment and treatment method, so this is just a guideline! Thank you!!!
