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Tempering is most often performed on steel that has been heated above its upper critical (A 3) temperature and then quickly cooled, in a process called quenching, using methods such as immersing the hot steel in water, oil, or forced-air. The quenched steel, being placed in or very near its hardest possible state, is then tempered to ...
Differential tempering begins by taking steel that has been uniformly quenched and hardened, and then heating it in localized areas to reduce the hardness. The process is often used in blacksmithing for tempering cutting instruments, softening the back, shaft, or spine, but simultaneously tempering the edge to a very high hardness. The process ...
A hypereutectoid steel contains more than 0.77% carbon. When slowly cooling hypereutectoid steel, the cementite will begin to crystallize first. When the remaining steel becomes eutectoid in composition, it will crystallize into pearlite. Since cementite is much harder than pearlite, the alloy has greater hardenability at a cost in ductility ...
In the case of ferrous metals, such as steel, annealing is performed by heating the material (generally until glowing) for a while and then slowly letting it cool to room temperature in still air. Copper, silver and brass can be either cooled slowly in air, or quickly by quenching in water. [1]
The process quenches the surface layer of the bar, which pressurizes and deforms the crystal structure of intermediate layers, and simultaneously begins to temper the quenched layers using the heat from the bar's core. Steel billets 130mm² ("pencil ingots") are heated to approximately 1200°C to 1250°C in a reheat furnace.
The metal part is then removed from the bath and cooled in air to room temperature to permit the austenite to transform to martensite. Martempering is a method by which the stresses and strains generated during the quenching of a steel component can be controlled. In martempering, steel is heated to above the critical range to make it all ...
Cryogenic tempering is two phase metal treatment that involves a descent and ascent phase, including a cryogenic treatment process (known as "cryogenic processing") where the material is slowly cooled to ultra low temperatures (typically around -300°F / -184°C), which is then optionally reheated slowly (typically up to +325°F / 162°C).
The term hardened steel is often used for a medium or high carbon steel that has been given heat treatment and then quenching followed by tempering. The quenching results in the formation of metastable martensite, the fraction of which is reduced to the desired amount during tempering. This is the most common state for finished articles such as ...