Two-frequency heat treatment and quenching process and device for D2 steel roller

Abstract

The invention relates to a two-frequency heat treatment and quenching process and device for a D2 steel roller. The two-frequency heat treatment and quenching process is conducted on a two-frequency induction quenching machine tool, the power frequency of an upper heating inductor is 50Hz, and the preheating power ratio is 1-3kw / cm2. A lower heating inductor adopts an intermediate frequency of 1000Hz, and the heating power ratio is 0.5-1.5kw / cm2. During induction quenching, the heating temperature of materials is generally larger than 800 DEG C, and the heat penetration depth delta 800 DEG C=500. According to the formula, the heat penetration depth of the power frequency for the roller is 71mm, and the diameter of the D2 steel roller is generally 80-120mm, and therefore the upper heating inductor can conduct heat penetration for the roller. The working frequency of the lower heating inductor is 1000Hz, the heating depth is 16mm according to the heat penetration formula, and therefore the depth of hardening layer is not less than 8mm. By limiting the quantity and the diameters of water spray holes in a water spray ring, the process controls the water spray quantity of quenching. Therefore, the D2 steel roller 3 can still maintain the original quenching and tempering tissue under the hardening layer, the surface hardness of the roller can be met, and the comprehensive mechanical property of the roller can also be met.

Description

technical field [0001] The invention relates to a heat treatment process and device, in particular to a dual-frequency pair D 2 The invention discloses a quenching process and device for heat treatment of steel, belonging to the technical field of heat treatment process. Background technique [0002] D. 2 Steel is the standard grade of the American Society for Testing and Materials, and the corresponding Chinese standard grade is Cr 12 Mo 1 V 1 , it is a ledeburite cold work die steel with high carbon, high chromium, high wear resistance, and has the characteristics of high brittleness and easy cracking. D. 2 Steel is mostly used as cold-rolled work rolls in multi-roll mills for rolling mirror stainless steel plates. Its hardness requirements are generally between HRC60°-62°, and the requirements for strength and wear resistance are also very high. In recent years, only some domestic companies can produce this kind of roll, but the production specification can only be ...

AI Technical Summary

Problems solved by technology

There are great disadvantages in the above process: 1. D on the multi-roll machine 2 Steel rolls are usually slender and long. They are hung vertically in a salt furnace for heating. When quenching out of the furnace, the upper part that comes out first is just the last quenching, resulting in high and low quenching temperatures and uneven quenching hardness, which not only affects the surface quality of the strip steel, but also It will lead to early peeling and scrapping of the roll. If the quenching is turned over and turned around, the quenching temperature will drop again, which is more likely to cause the roll to bend; 2. Quenching in the salt furnace is basically through quenching, and the roll has poor toughness and is easy to crack; The pollution is serious, the heat utilization rate is low, and the energy consumption is large

All in all, the use of a salt oven is very 2 The process of heating and quenching steel rolls is a backward process with high energy consumption and low production capacity, which cannot meet the technical requirements of modern industrial products.

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