Microstructure and Tribological Properties of Laser Forming Repaired 34CrNiMo6 Steel

Area of Science:

• Materials Science
• Metallurgy
• Surface Engineering

Background:

• 34CrNiMo6 steel is crucial for high-value components.
• Damage to these components necessitates effective repair strategies.
• Laser forming repair (LFR) offers a promising solution for steel structure repair.

Purpose of the Study:

• To investigate the feasibility and effectiveness of LFR for repairing 34CrNiMo6 steel.
• To analyze the microstructural, mechanical, and tribological properties of LFR-repaired 34CrNiMo6 steel.
• To compare the performance of LFR-repaired layers with the original substrate.

Main Methods:

• Deposition of five and 20 layers of 34CrNiMo6 steel using LFR technology.
• Microstructural analysis via optical microscopy and scanning electron microscopy.
• Phase analysis using X-ray diffraction.
• Microhardness testing using Vickers hardness tester.
• Tribological property evaluation through dry sliding wear testing.

Main Results:

• Successful deposition of 34CrNiMo6 steel layers via LFR.
• Microstructure of five-layer sample: bainite and retained austenite.
• Microstructure of 20-layer sample: bainite and retained austenite (top), ferrite and cementite (bottom).
• Wear rates: 12.89 × 10⁻⁶ (5-layer), 15 × 10⁻⁶ (20-layer), 23.87 × 10⁻⁶ mm³/N·m (substrate).
• LFR samples demonstrated significantly better wear resistance than the substrate.

Conclusions:

• LFR is an effective method for repairing 34CrNiMo6 steel components.
• The microstructure of LFR-repaired layers influences wear behavior.
• Laser forming repaired samples exhibit enhanced wear resistance, primarily due to abrasive wear mechanisms.
• LFR technology holds potential for extending the service life of high-value steel components.