1, ultra-clean steel production

Kobe Steel Kakogawa Works in Kobe Steel and smelting, casting for high-carbon chromium bearing steel. In addition to this more stringent steel refining process in order to minimize oxide and nitride inclusions completely apart, its the same with ordinary steel production process.

The full deploy spoliation and desulphurization of hot metal pretreatment of hot metal in the converter in the decarburization process. Oxidation converter slag is a slag. In order to reduce the oxide inclusions, slag is cut off; thereby oxide inclusions will not flow into the ladle. In refining (heating, degassing) and continuous casting, molten steel is more stringent than usual inert gas shielding to prevent the occurrence of secondary contact with air oxidation. In the refining process, due to very high basic slag, molten steel after full mixing, the oxide inclusions (mainly aluminum oxide) floating into the slag, the steel becomes more clean, only a small amount of mixture. In continuous casting, the Kobe factory tank heater to accelerate the use of steel in the middle of the mixture increased, Kakogawa plant is in the middle of the larger tank.

To reduce the nitride inclusions, it is necessary to make the minimum titanium content in steel. Mainly from titanium alloy, in particular, use to adjust the chemical composition of steel, chrome iron. Typically, the chromium in the ladle refining process added to the molten steel. As the oxygen content in molten steel is very low, and therefore the form of titanium dioxide (titanium dioxide) to remove titanium is very difficult. In Kobe Steel Company, ferrochrome is blowing in the converter to add and melt, but this time the oxygen content is very high, so the titanium reacts with oxygen to form titanium dioxide is then absorbed into the converter slag.

2, the performance of ultra-clean steel

52100 in the ultra-clean steel, the oxygen content can be controlled to an average of 4.1ppm, the average titanium content of 6.0ppm. Ultra-clean steel 52100 with the fatigue life of steel compared to the comparative test, L10 higher. In addition, a number of detection methods using ultra-clean steel and ordinary steel cleanliness were compared. By comparison, the ultra-clean steel and general cleanliness of the bearing steel is not very different; however, the fatigue life of ultra-clean steel is much longer than ordinary steel.