The reasons for the wear and tear of coated steel pipes are quite complex.
PVC-coated steel pipes require the preparation of welding samples according to the welding process, selecting welding materials as per the welding procedure card, and ensuring standardized plates are prepared. Cleaning, drying, and insulation are carried out as required. Personal protective equipment includes gloves, face masks, hammers, chisels, needle-nose pliers, angle irons, files, steel brushes, recording pens and paper, and timers. Equipment preparation involves selecting welding equipment, cutting machines, and vise clamps based on the chosen welding method. Measurement tools include bevel angle gauges and weld measurement scales. The bevel surface must be free of cracks, delamination, and other defects before welding. Prior to welding, remove oxides, oil, slag, and other harmful impurities from both sides of the bevel and the base material (apply chalk powder to the stainless steel side). Increase the cross-sectional area and length of the locating weld appropriately. Increase the welding current and decrease the welding speed during the locating weld. Welding operations must be carried out strictly according to the welding procedure card, with visual inspections of the pre-welding, welding process, and post-welding quality, and detailed welding records should be maintained (welding record sheets should follow a specific format and include analysis of welding quality and refinement of welding procedures. Common welding defects include the stainless steel side of the weld joint appearing blue or purple, indicating excessive heat input. In such cases, reduce the welding current, increase the welding speed, or employ multi-layer, multi-pass welding.
The plastic-coated steel pipes are焊接 according to the welding process, preparing materials before welding, ensuring standard plates and sheets, selecting welding materials based on the welding procedure card, and cleaning, drying, and insulating as required. The tools prepared include gloves, masks, hammers, chisels, needle-nose pliers, angle irons, files, steel brushes, recording pens and paper, and timers. The equipment is prepared by selecting welding equipment, cutting machines, and vise clamps based on the chosen welding method. Measurement tools, such as bevel angle gauges and weld measurement rulers, are also prepared. The bevel surface requirements for the positioning weld (the bevel surface must be free of cracks, delaminations, inclusions, etc.) Before welding, the oxide, oil, slag, and other harmful impurities on both sides of the bevel and base material should be removed (apply chalk powder on the stainless steel side). Increase the cross-section and length of the positioning weld appropriately. Increase the welding current and decrease the welding speed during the positioning weld. Welding operations: strictly follow the welding procedure card during welding, conduct visual inspections of the pre-welding, welding process, and post-welding quality, and maintain detailed welding records (welding record sheets in the format of Table X, analyze welding quality, and refine the welding process. Common welding defects include the stainless steel side of the weld joint being blue or purple, indicating excessive heat input. In this case, reduce the welding current, increase the welding speed, or use multi-layer, multi-pass welding.
The team has refined the welding process through discussions and exchanges, focusing on the welding operation process, the selection of welding parameters, and the appearance inspection of the post-welding quality. When machining plastic materials, if both the cutting speed and thickness are high, the friction at the tool's leading edge increases, leading to higher temperatures. If the tool's heat and wear resistance are slightly insufficient, a crescent-shaped indentation will form near the main cutting edge. During the wear process, the crescent indentation deepens and widens, gradually reducing the cutting edge strength of the plastic-coated steel pipe. The amount of wear at the leading edge is generally represented by the crescent indentation wear. When both the front and back surfaces are worn while machining plastic materials with a cutting thickness between the two, it is common for both surfaces to wear simultaneously, often resulting in deeper grooves near the main cutting edge close to the workpiece surface and the secondary cutting edge close to the tool tip. Abnormal wear of tools mainly refers to brittle fractures (such as chipping, breaking, spalling, cracking, etc.) and plastic fractures (such as plastic flow).
The primary reasons for tool wear are due to the improper selection of tool material,不合理 tool structure and manufacturing processes, inappropriate geometric parameters, incorrect cutting tool selection, and improper handling during tool sharpening or use. The cause of tool wear is that tools are subjected to cutting under high temperatures and pressures, and normal wear is unavoidable, often a combined result of mechanical, thermal, and chemical actions. The reasons for the wear of plastic-coated steel pipes are complex, with the main causes including: abrasion wear, also known as mechanical wear. The presence of high-hardness particles in the workpiece material, such as carbides, chip fragments, and hardened layers on the machined surface, causes wear when these hard particles scratch the tool surface, forming abrasion. This type of wear exists at all cutting speeds, but it is the primary cause of tool wear for low-speed cutting tools. Therefore, tool materials with higher hardness, more, finer, and evenly distributed carbide hard particles can enhance their resistance to abrasion wear.
