1. Material Through the multi-dimensional inspection of […]
Through the multi-dimensional inspection of the surface quality of raw materials, metallographic structure, decarburization layer, chemical composition, tensile strength, etc., the use of vacuum deoxidation treatment, non-metallic medium and other impurities, and high cleanliness materials.
2. Sphere forming (cold heading)
In the ball molding machine, the wire is cut into a certain length, and the ball is formed after compression by the female and male molds on the hemispherical ball seats on both sides. (Under normal temperature conditions, the wire is cut to a specific length and plastically deformed by the cold heading machine to form a ball billet)
The forged steel ball is sandwiched between two hard casting discs, and pressure is applied to rotate it to remove burrs and surface bands, and at the same time increase the surface roughness of the steel ball to make it preliminary spherical.
4. Heat treatment
The steel ball is carburized in the heat treatment furnace and then quenched and then tempered so that the ball has a certain carburized layer, hardness, toughness and crushing load. At present, some technologically advanced manufacturers use mesh belt heat treatment lines to effectively control the process parameters of quenching and tempering time and temperature through various instruments to ensure the stability and controllability of product quality.
A processing method in which steel balls collide with each other through a strengthening machine to make the surface of the steel ball plastically strengthened to increase the compressive stress and surface hardness of the steel ball.
6. Hard grinding
The surface quality and shape of the steel ball are further improved by grinding the iron plate and rotating the grinding wheel plate under a certain pressure.
7, preliminary research
Two cast iron primary grinding discs are used, then abrasives are added, and through certain pressure and mechanical movement, the surface quality of the precision specified by the process is achieved.
8. Appearance inspection
After 100% manual selection, plus AVKIO flaw detector: select all kinds of defect balls by three methods: photoelectric, eddy current, and vibration, such as surface defects (flat head, burr, cushion, rolling, cracking, burn, etc.), shallow surface Layer cracks, internal material defects.
9, fine research
Similar to the initial research process, two cast iron fine-grinding plates are used, and abrasives are added. Under certain pressure and mechanical movement, the margin is removed, and the precision and surface quality of the steel balls are further improved.
10. Cleaning and dehydration
The spiral cleaning machine and the lifting turnover box improve the cleaning quality and reduce the damage of the steel ball surface. In addition, it is necessary to continuously filter the cleaning liquid to ensure the cleanliness of the steel ball.
11. Photoelectric ball picking
The optical automatic appearance sorting machine judges the surface quality of steel balls and removes products with material defects and processing defects.
12. Finished product inspection
For each batch of steel balls, perform final inspections in accordance with the requirements of the process, such as the roundness, hardness, metallography, stress, etc. of the steel balls. Refer to the inspection standards for details.
13. Anti-rust packaging
Use anti-rust oil, spray anti-rust and complete the packaging according to the customer's packaging requirements.
At present, the steel balls with a diameter of 1/16 inch (about 1.6mm) and 2mm used in computers with high grade accuracy have an average surface roughness of only 0.002μm. (1μm is 1/1000mm.)
So how high is this precision? If we expand a steel ball with a diameter of 2mm to the size of the earth (the diameter of the earth is 12000km), its unevenness is only 12m. In fact, the earth has ups and downs of more than 10km (Everest 8850m, Mariana Trench 11000m). Therefore, the accuracy of the steel ball is obvious.
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