Vacuum heat treatment technology
Vacuum heat treatment furnace thermal efficiency is high, which can realize the rapid heating and cooling, which can realize no oxidation and decarburization, carburizing, can remove phosphorus crumbs on the surface of the workpiece, and has the effect such as degreasing degassing, so as to achieve the surface brightness purification effect.
Vacuum heat treatment, the combination of vacuum technology and heat treatment, refers to the whole and part of the heat treatment process under vacuum condition. Our country divides vacuum into low, medium, high and ultra high vacuum. Vacuum heat treatment can achieve almost all heat treatment process, such as quenching, annealing, tempering, carburizing, nitriding, during the quenching process can realize gas quenching, quenching oil, water nitrate quenching, quenching, etc., can also be vacuum brazing, sintering and surface treatment, etc. Vacuum heat treatment furnace thermal efficiency is high, which can realize the rapid heating and cooling, which can realize no oxidation and decarburization, carburizing, can remove phosphorus crumbs on the surface of the workpiece, and has the effect such as degreasing degassing, so as to achieve the surface brightness purification effect.
Generally speaking, the processed workpiece is heated slowly in the furnace, the internal thermal temperature difference is small, the thermal stress is small, and the deformation is small. High quality of products. Can reduce the cost, have the degassing effect, thus improve the mechanical performance and service life of the work. Good working environment, safe operation, no pollution and pollution. The treated workpiece has no hydrogen embrittlement hazard, and the stability and repeatability of the vacuum heat treatment process are good for titanium and refractory metal shell. This series of advantages, the development of vacuum heat treatment equipment and technology has been more and more attention and application.
General metal materials in the heating furnace in air, due to the existence of oxygen in the air oxidation, water vapor, carbon dioxide and other gases, these gases and metal oxidation is easy to make the heated surface of the metal oxide film or oxide skin, completely out of the original metallic luster. The gas also reacts with the carbon in the metal to decarbonize it. If the furnace contains carbon monoxide or methane gas, it will also add carbon to the metal surface. For the chemical nature very lively Ti, Zr and refractory metal W, Mo, Nb, Ta, etc., in the air heating furnace, in addition to generate oxide, nitride, hydride, to absorb the gas and internal diffusion to metal, metal material performance deteriorated badly. These oxidation, decarburization, carbon capture, inhalation and even corrosion are sometimes difficult to avoid in a controlled atmosphere furnace or salt bath furnace. In order to solve this problem, the usual practice is to leave the machining allowance before the heat treatment of the workpiece, and after the heat treatment, the oxidation and decarburization layer are removed.