Heat treatment

Annealing
Heat treatment that involves heating at a temperature that is higher than the austenitizing temperature, maintaining temperature and slow cooling.
Objectives: chemical, structural and mechanical equilibrium.
Full annealing
Heat treatment that involves heating up to Ac3 + 25-50 °C or Ac1 + 50-70 °C, maintaining treatment 1 hour for every 40 mm of thickness and then slow cooling in a 5-50°C/h furnace.
Objectives: maximum and optimal malleability when cold.
Isothermal annealing
Heat treatment that involves heating up to a temperature above the austenitizing temperature, rapid cooling at not less than 650-700°C, continue until transformation of austenite complete and then cooling, even rapidly.
Objectives: uniform structure due to the continuous constant temperature.
Endothermic annealing
Heat treatment that involves maintaining a temperature ±20/30°C from austenitizing temperature for about 30 hours.
Objectives: Increasing strength and utility.
Burning
Heat treatment that involved reaching 300-500°C.
Objective: Removing shearing oils from material.
Bluing
Process that involves treating the material at 550°C through esogas and water vapour.
Objectives: Improving resistance to rust.
Decarburizing
Treatment involves a reaction between oxygen and carbon through a nozzle that shoots out directly on the melted material.
Objectives: Passage from iron to steel reducing the percentage of carbon.
Stress reliving
Heat treatment that involves maintaining the material at a temperature between 150°C and 210°C.
Objectives: Reducing internal tension without altering hardness.
Case-hardening
Heat treatment that involves reaching 950°C.
Objectives: Improving steel’s resistance to wear.
Carbonitriding
Heat treatment that involves maintaining a temperature of about 775°C for 3/4 of an hour.
Objectives: Resisting wear when dry, permanent hardening until around 360°C.
Nitriding
Heat treatment that involves bringing steel to around 530°C and inserting nitrogen.
Objectives: Surface hardening of steel stable up to around 650°C, resistance to corrosion, dimensional stability.
Hardening
Heat treatment that involves an abrupt and rapid cooling of material after having brought it to a slightly higher temperature than austenitizing temperature.
Objectives: Obtaining greater mechanical and corrosive resistance, improving mechanical characteristics.
Bainite hardening
Quenching in heat bath at a temperature slightly higher than the beginning of martensite transformation.
Objectives: Stength, reducing tension.
Tempering
Process after hardening that consists in reheating the material after hardening to avoid the formation of cracks.
Objective: Reducing the negative effects of hardening.
Solubilizing
Rapid cooling of material.
Objectives: Improve strength and mechanical characteristics.
Age hardening
Process that follows hardening and consists in leaving material at room temperature.
Objectives: Elevating mechanical properties.
Phosphating
Uniform surface covering of material with a phosphate solution through a spray or bath.
Objectives: Corrosion resistance and predisposition for painting.