Study on the Influence of Compression Ratio on the Rail Contact Fatigue Resistance Property and Its Mechanism

Contact fatigue resistance properties of four commercial steel rails were systematically studied and compared. The contact fatigue limit cycles, fracture toughness, and fatigue crack growth rate of the corresponding rails with different compression ratios were tested and analyzed, which showed a close relationship between them. Moreover, microstructures of the rails were carefully observed by using the TEM to elucidate the scientific mechanisms. Observations and obtained results indicated that pearlite lamellar spacing further decreased with the rise of compression ratio, which greatly and rightly contributed to the improved fatigue resistance property.