Training skills for steel for bearings (1)

**Training Skills for Bearing Steel (1)** Home > Bearing Knowledge > Training Skills for Bearing Steel (1) Source: Bearing Network | Time: 2013-02-11 --- The reduction of oxygen content in bearing steel has a direct impact on the number of inclusions present, which significantly affects the fatigue life of the material. According to available data, there is a clear relationship between the oxygen content and the relative life (L10) of steel L10: **L10 (relative life) = 372 [O] - 1.6** Where [O] represents the oxygen content in the steel, measured in parts per million (ppm). One of the most significant improvements in steel production techniques has been the reduction of oxygen levels. In the early 1960s, oxygen content was around 30×10⁻⁶, but today it has been reduced to as low as 3–5×10⁻⁶. This improvement has led to an L10 value more than 30 times greater than before vacuum degassing. ### 1. Vacuum Degassing and Refining Techniques Outside the Furnace In 1964, the ladle degassing method was introduced. The process involved placing the ladle inside a vacuum chamber and using inert gas for stirring, reducing the pressure to 66.5 Pa (0.5 Torr). This lowered the oxygen content from (25–35)×10⁻⁶ to (15–20)×10⁻⁶. However, this method also stirred the alkaline slag, limiting the purity of the steel. To address this issue, the RH (Ruhrstahl-Hydroroll) method was introduced in 1968 under high vacuum conditions (13.3 Pa or 0.1 Torr). This technique effectively removed hydrogen and oxygen without disturbing the slag. When combined with a 60-ton high-power electric furnace, the oxygen content was further reduced to (8.3–15)×10⁻⁶. By 1974, the LF (Ladle Furnace) method was developed to complement ultra-high-power electric furnaces. This process included heating, stirring, and vacuum degassing within the ladle, allowing for precise control over slag composition, deoxidation, desulfurization, and dehydrogenation. Combined with RH, the oxygen content was reduced to (5–10)×10⁻⁶, which became essential for subsequent casting processes. Additionally, atomization and circulating vacuum degassing methods were also developed to enhance the efficiency of the process. ### 2. Vacuum Processing in Bearing Steel Production Vacuum treatment during steelmaking not only prevents oxidation but also helps in deoxidizing the molten steel, achieving higher purity compared to traditional methods. Some of the key techniques include: #### 2.1 Vacuum Induction Melting (VIM Method) In vacuum induction melting, high-quality scrap steel and alloyed steel grades are selected and placed into a small induction furnace. The furnace is then placed inside a large vacuum chamber equipped with a sealing hopper for adding required alloys. This method ensures minimal contamination and better control over the chemical composition. --- **Related Bearing Knowledge** The full-rolling cylindrical roller bearing plays a crucial role in the operation of bearing grinding machines and their control systems. It ensures smooth timing and helps in diagnosing rolling bearing faults. Understanding these aspects is essential for maintaining the performance and longevity of bearings. --- This article is sourced from China Bearing Network. Please visit http://www.chinabearing.net for more information. Previous: Bearings for Diesel Engine Hydraulic Transmission System – Repair Conditions and Methods for Rolling Bearings

Wall Washer Light

Wall Washer Light,Wall Washer Led Light,Led Wall Washer Outdoor Light,Wall Wash Light Fixture

EV LIGHT Guangzhou Co., Ltd , https://www.evlightpro.com