Normalizing heat treatment method of nodular cast iron for automobile covering part mold

Abstract

The invention aims to provide a normalizing heat treatment method of nodular cast iron for an automobile covering part mold. The normalizing heat treatment method comprises the following steps that the automobile covering part mold is put into a heat treatment furnace, and the heat treatment furnace is started at the heating rate of 10 DEG C / min; the temperature rises to 870 DEG C-930 DEG C, heat preservation is conducted for 2 hours, then a furnace door is opened, and furnace cooling is conducted for 30 minutes; and the furnace door is closed tightly, the temperature is increased to 720 DEG C at the rate of 10 DEG C / min, heat preservation is conducted for 1 h, and then cooling is conducted. According to the heat treatment technology, the normalizing process efficiency is high, and meanwhile the obtained automobile covering part mold is good in structure uniformity and high in strength.

Description

technical field [0001] The invention relates to the field of automobile cover molds, in particular to a normalizing heat treatment method for nodular cast iron used in automobile cover molds. Background technique [0002] The heat treatment process is an important basic technology in the machinery industry. Usually, important connecting parts such as shafts, gears, connecting rods and important molds must undergo heat treatment. Moreover, as long as the material selection and heat treatment are appropriate, the parts will be The service life is doubled or even dozens of times increased. If the material selection and heat treatment are done properly each time, the effect of getting twice the result with half the effort can be achieved. Heat treatment is of great significance for exerting the potential performance of metal materials, improving metal quality, saving materials, reducing energy consumption, improving product life, and promoting economic development. [0003] As ...

AI Technical Summary

Problems solved by technology

There are mainly the following deficiencies: 1. Large energy consumption and low energy utilization rate; 2. Outdated heat treatment production technology and equipment; 3. Poor product quality, low production efficiency, and serious pollution.

At present, after high-frequency impact, the automobile panel mold will produce weak deformation due to insufficient strength, which will affect the dimensional accuracy. Its performance can be improved by designing the heat treatment process.

The prior art patent CN110157868A discloses a heat treatment process for ductile iron piston castings. The nodular cast iron piston castings are annealed twice before austenitic strengthening, which solves the problem that the ductile iron piston castings have a large white tendency and internal defects during the casting process. High stress, it is difficult to obtain pure ferrite and pearlite, and obtain high toughness ductile iron piston castings

However, the current heat treatment process of ductile iron for automobile panel molds has many unsatisfactory aspects. The normalizing process efficiency of the traditional heat treatment process for automobile panel molds is relatively slow. At the same time, the obtained automobile panel molds have poor structure uniformity and low strength. Its comprehensive performance has a large room for improvement

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