After a chemical engine cylinder liner is worn, it can be effectively repaired through a standardized honing process, provided that specific conditions are met. By strictly controlling key steps throughout the repair process, it can be ensured that the repair does not affect sealing performance. However, this repair is not without limitations. First, a comprehensive assessment of the chemical engine cylinder liner's wear level, damage type, and substrate condition is required. Due to its long-term exposure to corrosive media, wear can often be accompanied by localized corrosion pits and microcracks. Honing repair is only feasible if wear does not exceed the substrate's machinability and there is no irreversible damage such as severe cracks, corrosion penetration, or excessive wall thinning. This is the primary prerequisite for ensuring the effectiveness of the chemical engine cylinder liner repair and sealing performance.
Before officially beginning the honing repair, pretreatment of the chemical engine cylinder liner is particularly critical. The inner surface of a chemical engine cylinder liner is susceptible to carbon deposits and oil stains from combustion or media reactions, as well as metal debris from wear. Some surfaces may also contain residual corrosive media. Failure to thoroughly remove these impurities will not only affect precision control during the honing process but may also cause new scratches during honing, disrupting the smoothness of the inner surface. Therefore, specialized cleaning agents and tools are required to thoroughly clean the inner surface of the chemical engine cylinder liner. The inner surface should also be inspected for hidden corrosion defects. If the depth of the localized corrosion pits is within the machinable range, they can be removed by honing. If they exceed the machining allowance, pre-treatment such as repair welding is required to prevent subsequent repairs that may cause sealing problems due to corrosion defects.
Precisely adjusting the honing process parameters directly determines the performance and sealing effectiveness of the repaired chemical engine cylinder liner. The appropriate abrasive hardness and grit size should be selected based on the chemical engine cylinder liner's material (such as alloy cast iron, ductile iron, etc.) and the original surface treatment (such as chrome plating or nitriding). Improper abrasive selection can lead to excessive wear of the chemical engine cylinder liner's inner wall or substandard surface finish, which in turn affects the sealing fit with the piston rings. Furthermore, the feed rate and speed during honing must be coordinated to ensure that a uniform cross-honing texture is formed on the inner wall of the chemical engine cylinder liner while removing the worn surface layer. This texture not only increases the contact area between the piston ring and the cylinder wall, enhancing sealing performance, but also retains lubricant, reducing friction and wear between the piston ring and the cylinder wall during chemical engine operation, preventing further seal failure due to increased friction.
Post-repair quality inspection and corrosion protection are crucial supplements to ensure the sealing performance of chemical engine cylinder liners. After honing, the inner wall of the chemical engine cylinder liner must be inspected for roughness, roundness, and cylindricity. Roughness must be within a suitable range for piston ring sealing. Excessive roughness can lead to seal gaps, while excessive fineness can hinder oil retention. Excessive deviations in roundness and cylindricity can cause uneven contact between the piston ring and the cylinder wall, leading to localized insufficient sealing pressure. Furthermore, since chemical engine cylinder liners must withstand corrosive media, honing may remove portions of the original corrosion-resistant coating. In this case, a new, compatible corrosion-resistant coating must be applied by spraying or electroplating. Ensure the coating is uniform in thickness and securely bonded to prevent corrosive media from penetrating through coating defects, exacerbating wear on the inner wall, and damaging the seal structure.
Post-repair assembly also requires strict control over the sealing requirements of the chemical engine cylinder liner. Before assembly, the mating surfaces between the chemical engine cylinder liner and the cylinder block must be cleaned to ensure they are free of residual impurities, preventing loose fit. During installation, the press force and coaxiality of the chemical engine cylinder liner must be controlled to prevent deformation of the cylinder liner and damage to the geometric accuracy of the inner wall due to installation deviations. The sealing gaskets on the upper and lower ends of the chemical engine cylinder liner must also be inspected to ensure they are intact and fit tightly against the mating surfaces. This prevents leakage of chemical media or coolant through the gap between the cylinder liner and the cylinder block. While this leakage does not directly originate from the seal on the cylinder liner's inner surface, it can affect the overall sealing performance of the chemical engine and requires coordinated control during the honing repair process.
Finally, the repaired chemical engine cylinder liner undergoes a test run to verify the stability of its sealing performance. After assembly into the chemical engine, it is operated for a period of time under rated operating conditions. The sealing effectiveness is assessed by monitoring indicators such as changes in medium pressure, leakage, and the presence of chemical media in the lubricating oil. If the pressure is stable during operation, there is no sign of leakage, and the piston ring wear is within the normal range, it means that the honing repair has restored the performance of the chemical engine cylinder liner and ensured the sealing reliability. If a leakage problem exists, it is necessary to review the honing process, surface quality or assembly links, identify and resolve the hidden dangers, and ensure that the repaired chemical engine cylinder liner is fully adapted to the rigorous working requirements of chemical engines, achieving the dual guarantee of wear repair and sealing performance.
