Laser cladding repair processing for oil drill pipes is an efficient repair technology. This process primarily utilizes a high-energy-density laser beam to rapidly melt pre-coated alloy powder on the damaged area of the drill pipe, followed by cooling and solidification to form a metallurgically bonded cladding layer.

I. Background of Laser Cladding Repair Processing for Oil Drill Pipes

During downhole operations, oil drill pipes are exposed to high temperatures, high pressure, and highly corrosive environments. They are subjected to erosion from drilling fluids and mud, as well as impacts and friction, which can lead to surface issues such as cracks, wear, and corrosion. These problems affect the safety and efficiency of drilling operations. Laser cladding repair processing technology can effectively address these issues.

II. Methods of Laser Cladding Repair Processing for Oil Drill Pipes

1. Preliminary Preparation: Pre-treat the drill pipe through steps such as cleaning, rust removal, and degreasing to ensure a strong bond between the cladding layer and the base material. Based on the drill pipe's material and usage requirements, select appropriate laser cladding powder, such as iron-based stainless steel alloy powder.

2. Preheating Treatment: Before laser cladding, preheat the starting end of the drill pipe using tools like resistance heating furnaces or flame torches. Control the preheating temperature between 300°C and 450°C, with a preheating length of at least 200 mm and a preheating time of 0.5 to 2 hours. This ensures a strong metallurgical bond between the cladding powder and the base material, preventing cracks at the starting end.

3. Cladding Operation: Use laser cladding equipment to uniformly deliver the selected metal powder onto the drill pipe surface via a powder feeding device. Simultaneously, employ a high-energy laser beam to rapidly melt, diffuse, solidify, and cool the powder, forming a cladding layer on the drill pipe surface that is highly hard, corrosion-resistant, wear-resistant, and high-temperature-resistant. The thickness of the cladding layer is generally ≥1.5 mm.

4. Post-Treatment: After cladding, perform turning on the cladding layer surface to remove the oxidized layer, followed by grinding. This ensures that the surface of the shaft component is fully covered with a cladding layer of ≥0.2 mm thickness, achieving surface smoothness and dimensional accuracy to meet the requirements for wear and corrosion resistance.

III. Advantages of Laser Cladding Repair Processing for Oil Drill Pipes

1. Extended Service Life: Significantly improves the durability and efficiency of drill pipes, extends their service life, and reduces replacement costs.

2. Enhanced Performance: The cladding layer has a dense structure, free of cracks and bubbles, with excellent strength and toughness. It greatly enhances the hardness, wear resistance, corrosion resistance, and fatigue resistance of the drill pipe.

3. Precise Repair: Enables precise repair of localized wear or damage on the drill pipe, restoring its original dimensions and shape while minimizing material waste.

4. Environmental and Energy Efficiency: This is a green and environmentally friendly process technology with a small heat-affected zone, minimal impact on the base material's properties, and low energy consumption during processing.