High-grade car precision bearing steel ball fabrication process

Abstract

The invention discloses a process for manufacturing a precision bearing steel ball used in a high-grade automobile. The process comprises the following steps of the selection of raw materials, the cold heading and forming of ball billets, the heat treatment, the surface strengthening, the preliminary lapping and flaw detection, the super lapping of a resin wheel, the cleaning, the rust protection and the packaging; by technologies of the selection of raw materials, the forming of ball billets, the surface strengthening and the super lapping of a resin wheel, the surface quality and the geometric accuracy of the steel ball are further improved, thereby improving the quality of products.

Description

technical field [0001] The invention relates to a manufacturing process of a steel ball for cars, in particular to a manufacturing process of high-precision, wear-resistant and impact-resistant high-grade car-specific precision bearing steel balls made of molded GCr15 bearing steel. Background technique [0002] At present, the steel balls for cars on the market are relatively traditional in the selection of raw materials, the cold heading process of the ball billet and the surface strengthening process. The raw materials are generally ordinary bearing steel, and its ordinary material makes the steel itself not wear-resistant and impact-resistant; in the billet forming process, the raw materials are directly made into circular billets, billet rings and poles. Column, the quality of its steel ball forming cannot be guaranteed, and the material loss increases due to the ring belt of the ball billet. In addition, the entire process of ball forming by this method, including que...

AI Technical Summary

Problems solved by technology

The raw materials are generally ordinary bearing steel, and its ordinary material makes the steel itself not wear-resistant and impact-resistant; in the billet forming process, the raw materials are directly made into circular billets, billet rings and poles. Column, the quality of the steel ball forming cannot be guaranteed, and the material loss increases due to the ring belt of the ball billet

In addition, the entire process of ball forming by this method, including quenching and tempering processes, cannot effectively improve the plasticity of the material, change the stress state, and make the product prone to cracks; the principle of steel ball strengthening in the surface strengthening process is to use mechanical methods to strengthen the steel. The surface of the ball is impacted with a certain force and time to form a strengthening layer with a certain depth, and the residual stress is controlled between 800 and 1000Mpa. The traditional method is to mechanically impact the steel ball, but the size and distribution of the residual compressive stress after the impact Unreasonable, tensile stress is generated during work, which causes cracks in the steel ball during use, increases the fatigue of the steel ball, and shortens the life of the steel ball; finally, in the process of lapping, the traditional lapping method is: ordinary The geometric accuracy of the steel balls is produced and improved by the traditional iron plate grinding method in the subsequent processing, but because the iron plate is gray cast iron, there are problems such as uneven structure, different hardness and softness, impurities, etc., resulting in scratches and bumps on the surface of the steel balls. Unfavorable factors such as injuries, burns, and geometric accuracy that cannot meet the requirements

Surface burns, especially secondary quenching burns and secondary tempering burns, are a major problem affecting the life of steel balls, and failures such as premature peeling and block loss will occur during use.