The quenching of alloy steel pipes is to heat the alloy steel pipes to a temperature above the critical temperature Ac3 (hypoeutectoid alloy steel pipes) or Ac1 (hypereutectoid alloy steel pipes), keep it warm for a period of time, make all or part of it austenite, and then heat it to a temperature greater than A heat treatment process in which the critical cooling rate is quickly cooled to below Ms (or isothermally near Ms) to undergo martensite (or bainite) transformation. The solid solution treatment or heat treatment process with rapid cooling process of aluminum alloy, copper alloy, titanium alloy, alloy steel pipe and other materials is usually called quenching.
Due to the impact of rapid heating on the organizational structure of alloy steel pipes, the traditional quenching and cooling process is no longer fully applicable. The new quenching process should be suitable for the following conditions.
The hardness of the quenched workpiece affects the quenching effect. The HRC value of quenched workpieces is generally measured using a Rockwell hardness tester. The HRA value can be determined for quenched thin-hard large-diameter alloy tube sheets and surface-quenched workpieces, while quenched large-diameter alloy tube sheets with a thickness less than 0.8mm, shallow surface-hardened workpieces, and quenched large-diameter alloy pipe rods with a diameter less than 5mm can be modified. Use a surface Rockwell hardness tester to measure its HRC value.
Quenching cooling should have rapid cooling conditions. Since rapid heating increases the critical quenching cooling rate of alloy steel pipes, in order to obtain satisfactory quenching, alloy steel pipe manufacturers must have the ability to exceed the traditional critical quenching cooling rate. Only with this kind of strip can we avoid spray quenching in the 650~400C area where austenite decomposition is dangerous. Various types of quenching media can be used, including water, compressed gas, synthetic quenching liquid, etc. Select the corresponding quenching according to different conditions to achieve good quenching effect.
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