Strona: Heat Treatment Laboratory / Katedra Odlewnictwa i Spawalnictwa

• The furnace is controlled by a digital PID controller with the possibility of programming several steps of heat treatment. Overheating protection (EN 605 19-2) adjustable in a wide range. The furnace reaches a maximum temperature of 1800°C. It has very fast heat-up time, durable aluminum oxide insulation and molybdenum disilicide heating elements. Due to these features, the furnace ensures the stability and accuracy of heat treatment.

• The N 61 / H furnace enables heat treatment up to 1280°C. The PID controller allows to program 9 segments with 20 steps of heat treatment and a time delay. There is a possibility of carburizing and nitriding. We have two furnaces of this type.

• Model HD2108.2 by Delta OHM with two K-type thermocouples. It can be changed to different thermocouples and two tests at the same time. There is a possibility to connect and save the results on the computer.
• Dostmann Electronic P700 series model with K type thermocouple. It can be changed to different thermocouples. There is a possibility to connect and save the results on the computer.

The term hardening of steel is defined as the tendency to create a martensitic structure, where the hardened zone is defined as a zone containing at least 50% martensite. The hardness of a zone with a structure containing 50% martensite, i.e. the so-called semi-martensite zone, is called the critical hardness.

Hardenability is closely related to the rate of cooling of the steel from the austenitizing temperature. A martensitic structure is obtained at a cooling rate greater than or equal to the critical rate, i.e. the lowest rate that conditions the formation of a martensitic structure only.

From Jominy's end quench test one can read:

• the maximum hardness of steel, the nature of changes in hardness,
• so, after appropriate conversion, other mechanical properties,
• critical diameter in a given cooling medium and, using appropriate monograms, the ideal critical diameter.

• The Termetal device with a power of 15kW enables induction heating of bars and ends of bars, flat bars, pipes and others.