1. Different steel composition
- Chrome-plated bearing steel rods: the uniformity of the chemical composition of the bearing steel, the content and distribution of non-metallic inclusions, and the distribution of carbides are all very strict. It is one of the most stringent steel grades in all steel production.
- CK45 steel chrome-plated rod: It is a high-quality carbon structural steel, corresponding to the Japanese standard S45C, the American standard: 1045, and the German standard C45. Its characteristic is that it has higher strength and resistance to deformation than ordinary A3 steel.
2. Different mechanical properties
- Bearing steel chromium-plated rod: Mainly implement GB/T18254-2002 standard and Laiwu Steel GCr15JD quality agreement adapted to the requirements of precision forged bearing users. The quality requirements of GCr15JD agreement are stricter than the GB/T18254-2002 standard, and GCr15JD requires oxygen content ≤10ppm , The central segregation level is less than or equal to 1.0, the composition control, fixed length and size deviation are all stricter than the GB/T18254-2002 standard.
- CK45 steel chrome-plated bar: The recommended heat treatment system for CK45 steel specified in the GB/T699-1999 standard is 850℃ normalizing, 840℃ quenching, and 600℃ tempering. The achieved performance is that the yield strength is ≥355MPa.
3.Process is different
- Bearing steel chromium-plated rod: 50 tons and above UHP electric furnace smelting 60 tons and above LF furnace refining 60 tons and above VD furnace vacuum treatment, alloy steel billet or rectangular billet continuous casting (260mm×300mm, 180mm×220mm), slow cooling or Finishing inspection and storage of hot rolled rolled products.
- CK45 steel chromium-plated rod: 40Cr/5140 steel should be oil-cooled after quenching. 40Cr/5140 steel has good hardenability, and can be hardened when cooled in oil, and the deformation and cracking tendency of the workpiece are small. However, under the condition of tight oil supply, small enterprises can quench the workpieces with uncomplicated shapes in water, and no cracks are found, but the operator must strictly control the temperature of the inlet and outlet water based on experience.
Source:Mechanical professional literature.
Editor:Ali
Post time: Nov-16-2021