lämmönkäsittelymenetelmän

Lämpökäsittelymenetelmä (heat treatment method) refers to a group of processes used to alter the physical and sometimes chemical properties of a material through controlled heating and cooling. These methods are primarily applied to metals, but also to ceramics and other materials, to achieve desired characteristics such as increased hardness, improved ductility, enhanced strength, or reduced internal stresses. The specific outcome depends on the material composition, the temperatures reached, the rate of heating and cooling, and the duration of the treatment.

Common heat treatment processes include annealing, which involves heating a material to a specific temperature and then cooling it slowly to soften it, relieve internal stresses, and improve its ductility. Hardening, on the other hand, typically involves heating a metal to a critical temperature and then rapidly cooling it, often in water or oil, to increase its hardness and strength. Tempering is usually performed after hardening to reduce brittleness and improve toughness by reheating the material to a temperature below its critical point and then cooling it. Normalizing involves heating a steel to a temperature above its critical point and then cooling it in still air, refining the grain structure and improving uniformity. Other methods like case hardening aim to create a hard outer layer while keeping the core tough. The choice of heat treatment method is crucial for tailoring a material's performance to specific applications.