Preparation technology of thermal insulation coating on internal combustion engine forging steel piston top

Abstract

The invention discloses a preparation technology of thermal insulation coating on internal combustion engine forging steel piston top. A layer of preprocessing aluminum coating is located on the surface of a piston body by electroplating or plasma spraying. The thickness of the electroplating or plasma spraying is 200 mu + / - 50 mu. An anodic oxidation or a micro-arc oxidation is made on the surface of the preprocessing aluminum coating, The thickness of processing is from 40 mu to 120 mu. The roughness is within Ra 1.6. According to the thermal insulation coating of the preparation technology of thermal insulation coating on internal combustion engine forging steel piston top, the top temperature can be decreased from 30 DEG C to 50 DEG C. The coking problem of coolant oil can be efficiently resolved. The experience achieves batch quantity verification and the effect is good.

Description

technical field [0001] The invention relates to the field of heat-insulating coatings for pistons, in particular to a preparation process for a heat-insulating coating on the top of a forged steel piston for an internal combustion engine. Background technique [0002] As the engine emission requirements become more and more stringent, the explosion pressure continues to increase, causing the thermal load and mechanical load on the top of the piston to continue to increase, especially for heavy-duty diesel engine pistons, which are designed with the original aluminum alloy structure, and the top often cracks and melts and other failures seriously affect the reliability of the engine. Some engine aluminum alloy pistons use top anodizing technology to reduce the top temperature, which still cannot meet the requirements of engine reliability. [0003] With the continuous emergence of forged steel structure pistons, steel pistons are currently showing a momentum of rapid developm...

AI Technical Summary

Problems solved by technology

Since the continuous top temperature of the piston exceeds 320°C, and because the thermal conductivity of steel is relatively large, the temperature of the inner cooling oil channel near the top area, especially the combustion chamber area, is relatively high, which makes the cooling oil easy to coke, and the coking accumulation for a long time is easy to block The internal cooling oil passage causes the top temperature of the piston to rise due to cooling failure, which exceeds the fatigue limit of the steel, resulting in cracking at the top