VACUUM HEAT TREATMENT FURNACE, AND METHOD AND APPARATUS FOR MEASURING CARBON CONCENTRATION IN ATMOSPHERE HAVING REDUCED PRESSURE

摘要

PURPOSE: Provided is a vacuum heat treatment furnace wherein furnace constituting materials are not deteriorated by carburizing when vacuum carburizing is carried out and which thermal energy efficiency for a subject to be treated is improved. CONSTITUTION: The vacuum heat treatment furnace comprises a furnace shell(1); a casing(2) arranged inside the shell(1); and a heat insulating layer formed of thick plate-like or multilayered alumina silica ceramic fiber blankets(3) and(4) arranged inside the casing(2) and a thin plate-like composite alumina ceramic material(5). The furnace also comprises a heater(7) positioned in a heating chamber surrounded by the heat insulating layer. In the heating chamber, a fan(8) used to forcibly convect the atmospheric gas in the heating chamber when the temperature of the subject to be treated is raised and lowered and the subject is heat-treated and formed of high-strength carbon fibers, a roller(11) for transporting the subject, and an easily exchangeable tray guide which protects the surface of the roller(11) are provided. In addition, a flapper(13) which is formed of high-strength carbon fibers and used for detecting the position of the subject is also provided in the heating chamber.