Hardness: Hardness is the measurement of the steel’s resistance to indentation by pressing into the surface of the steel a specific object—such as a steel or molybdenum ball or diamond indenter—using very specific loads.
Hardness is simply the resistance to indentation as determined by load over area of the specific indenter.
Heat Treatment: Heat treatment is any method of applying heat to a metal. The source of heat can be gas, oxy-acetylene, electricity micro-wave, laser, etc. There are always three aspects to the heat treatment cycle: (1) heat up to the selected temperature, (2) soak at that temperature and (3) cool down from that temperature.
Holding Temperature: The holding temperature is that temperature that has been selected for the specific process underway. The term always refers to time at temperature, meaning the time that the steel reaches the selected process temperature, not when the furnace reaches temperature.
Hypo-Eutectoid Steel: Hypo-eutectoid steel has a carbon content of less than 0.77% present in solution.
Hardenability is the property of steel that determines the depth and distribution of hardness induced by quenching from the austenitizing temperature. Hardenability should not be confused with hardness as such or with maximum hardness. Hardness is a measure of the ability of a metal to resist penetration as determined by any one of a number of standard tests (Brinell, Rockwell, Vickers, etc). The maximum attainable hardness of any steel depends solely on carbon content and is not significantly affected by alloy content. Maximum hardness is realized only when the cooling rate in quenching is rapid enough to ensure full transformation to martensite.
Post weld heat treatment is designed to return a metal as near as possible to its prefabrication state of yield, ultimate tensile and ductility.
The rate of temperature rise, holding time at temperature and rate of cooling are vitally important. For this reason, furnace thermocouples must measure metal temperature, not furnace atmospheric temperature.
Heat treatment of any type must be a planned, systematic action. Poorly performed heat treatment can result in far more harm to material than any good which may result.
Test coupons must be subjected to the identical conditions as the vessel or part in order to obtain meaningful tensile and toughness (Charpy) test results.
thanks for your definition, I got it
thanks for your definition,They are very accurate
Thank you for your definition, it is very accurate
Thanks for defining some of the metallurgical terms that I hear sometimes. What are the applications of heat-treatment? I have a friend who wants the hardest wedding band possible; is heat treatment a viable solution? Or would it be unwise to have a band that hard?
at first,Heat treatment process is widely used in machinery industry,in order to meet the requirements of a variety of mechanical design，but it has a hardness limits， I don’t know how much the hardness requirement your friend wants is and what the material is:-) maybe we can discuss if you tell me more details about his or her wedding band:-）I’m very glad to help you