Bucket Teeth 20U7013251 Replacement Parts Applicable To PC56

Mechanisms and Preventive Measures for Equipment Fatigue Wear

I. Fatigue Wear Mechanisms

Crack Initiation and Propagation

Under cyclic stress, grain slip within the material leads to microcrack formation (preferentially initiated at stress concentration points). The crack tip develops a plastic deformation zone due to stress cycling, gradually propagating into macrocracks.

Oxidation Synergy

In high-temperature environments, mismatched hardness between oxide films and base metals causes film fracture, accelerating fatigue crack propagation and inducing corrosion fatigue.

Localized Stress Concentration

Surface roughness exceeding Ra 1.6 μm can increase stress concentration factors at peaks by 3-5 times, significantly reducing fatigue life.

II. Preventive Measures

Material Optimization

Select fatigue-resistant materials (e.g., 40CrNiMoA steel with fatigue limit ≥800MPa)

Apply surface strengthening treatments (shot peening can enhance residual compressive stress layer depth to 0.3mm)

Structural Design Improvements

Avoid sharp transition radii (minimum radius ≥ 1.5 times cross-sectional thickness)

Employ streamlined structures to reduce stress concentration factors (theoretical value < 1.5)

Lubrication and Maintenance

Use lubricants containing extreme pressure additives (e.g., sulfur-phosphorus additives, oil film strength ≥ 800 MPa)

Regularly monitor vibration spectra (shutdown required for abnormal frequency shifts > 10%)

Environmental Control

Apply ceramic coatings to high-temperature components (temperature resistance ≥1200°C)

Implement cathodic protection in corrosive environments (protection potential -0.85 to -1.05V vs. Cu/CuSO₄)

Typical Application Case: Wind turbine main shafts treated with carburizing and quenching (surface hardness 58-62 HRC) combined with online vibration monitoring achieved a 3x increase in fatigue life.