The first stage: Before the 1970s, China could not talk about the process, it was simple and rough;
The second stage: 1971-1983: mainly the production of iron-cut balls, the process is simple and backward;
The third stage: 1983-1990: began to recognize the importance of science, and gradually developed to scientific, but the steel ball has a high rate of breakage. During this period, the importance of the internal stress of the steel ball has not been fully recognized;
The fourth stage: from 1991 to 2004, the process technology gradually matured and the products went to the world. The carbon steel, the combined steel and even the bainite steel ball began to be researched and went to the market with a systematic steel ball quenching process. The equipment for making the screw device uses the salt bath tempering technology, and the pioneering start of the technological transformation is gradually changed from the traditional coal heating method to the gas generating furnace-heavy oil heating furnace-natural gas heating furnace-electric furnace production. process;
The first three stages, especially the first and second stages, the ball mill of more than 6m has just started, and the mine is gradually rising. Therefore, after 2000, the real stage of steel ball production and quality is actually started.
The fifth stage: 2005-2010, driven by industrial production, increase production, China's steel ball is gradually recognized by the world's large mines, to the world, began to take a scientific approach;
The sixth stage: from 2010 to the present, the development is very fast. Take Zhangqiu, the hometown of forging in Shandong, as an example. From 2000, the annual output is 10,000 tons. The development of more than ten years now reaches 300,000 tons. Constantly refreshed, the material is continuously optimized, the mill used in the mine is constantly increasing, and the requirements for the steel ball are also improving with the times.