Views: 27 Author: Site Editor Publish Time: 2023-03-29 Origin: Site
Continuous aluminum alloy quenching furnace is suitable for solution treatment and aging treatment of large and medium-sized aluminum alloy product parts. This equipment is specially used for mass solidification and aging heat treatment of aluminum castings and profiles. This equipment is used in conjunction with electrical control and has a high degree of automation.
The continuous aluminum alloy quenching furnace is composed of a heating furnace cover and a movable bottom frame. A crane is installed on the top of the square (or round) furnace hood, and the basket can be hoisted to the furnace through chains and hooks. The furnace hood is supported by section steel, and there is a pneumatic (or electric) operated furnace door at the bottom.
Jiahangaero learned that the underframe located under the furnace hood can be moved and positioned along the track, and the quenching water tank and material basket are mounted on the underframe. During production, move the material basket on the bottom frame to the bottom of the furnace cover, open the furnace door, put down the chain and hook to hang the material basket into the furnace, close the furnace door and start heating. For quenching, first move the water tank on the bottom frame to the bottom of the furnace cover, then open the furnace door, put down the chain, and quench the material basket (workpiece) into the water.
Working Principle Of Continuous Aluminum Alloy Quenching Furnace
Jiahangaero shows that the cooling rate in quenching is an important factor that can affect the quality of quenching and determine the residual stress, and it is also a factor that can have an important and even decisive influence on quenching cracks.
In order to achieve the purpose of quenching, it is usually necessary to accelerate the cooling rate of parts in the high temperature section, and make it exceed the critical quenching cooling rate of steel to obtain martensite structure. As far as residual stress is concerned, this can reduce the tensile stress on the surface of the workpiece and achieve the purpose of inhibiting longitudinal cracking because it can increase the thermal stress value that offsets the effect of tissue stress. Its effect will increase with the acceleration of high temperature cooling rate. Moreover, in the case of hardening, the larger the cross-sectional size of the workpiece, although the actual cooling rate is slower, the risk of cracking is actually greater.
Jiahangaero understands that slow cooling in the martensitic transformation zone alone is not sufficient to prevent the formation of longitudinal cracks. Under normal circumstances, cracks can only occur in non-hardenable parts. Although the overall rapid cooling is the necessary formation condition, the real cause of its formation is not the rapid cooling (including the martensitic transformation zone) itself, but It is the local position of the quenched part (determined by the geometric structure), and the cooling rate in the high temperature critical temperature zone is significantly slowed down, so it is not caused by hardening. The transverse and longitudinal splits that occur in large non-hardenable parts are caused by the residual tensile stress with thermal stress as the main component acting on the center of the quenched part, and at the center of the unhardened cross section of the quenched part, cracks are first formed and are formed by caused by expansion from the inside out. In order to avoid such cracks, water-oil two-liquid quenching process is often used. In this process, the rapid cooling in the high temperature section is implemented.
The purpose of Jiahangaero reminder is only to ensure that the outer metal obtains a martensitic structure. From the perspective of internal stress, rapid cooling is harmful and not beneficial. Secondly, the purpose of slow cooling in the later stage of cooling is not mainly to reduce the expansion rate and structural stress value of the martensitic transformation, but to minimize the cross-section temperature difference and the shrinkage speed of the metal in the center of the cross-section, so as to reduce the stress value and the final The purpose of inhibiting quenching cracking.