Does Heat Treatment Double the Performance of S45C Steel Plate?

S45C steel plate, defined under the JIS G 4051 standard, is a medium-carbon steel that already offers solid mechanical performance in its raw form. But when subjected to proper heat treatment, its strength, hardness, and durability can increase dramatically—often making it feel like its performance has doubled.

The process typically includes quenching and tempering, which significantly enhances the steel’s tensile strength, yield strength, and surface hardness. For instance, the tensile strength of untreated S45C steel plate may be around 570–700 MPa, but after quenching and tempering, it can reach 750–850 MPa or higher, depending on the cooling medium and tempering temperature.

This improvement makes heat-treated S45C steel plate ideal for high-load applications such as gears, shafts, pins, and machine parts that require not only strength but also resistance to wear and fatigue.

In addition to strength, heat treatment improves toughness and dimensional stability, which are critical for precision machining. It also increases the steel’s resistance to deformation under stress, extending the service life of components and reducing failure risk.

Conclusion:
Yes—heat treatment can nearly double the performance of S45C steel plate in terms of mechanical strength and durability. For engineers and manufacturers looking to upgrade material performance without switching to alloy steels, heat-treated S45C steel plate offers an excellent balance of cost, strength, and versatility.