Technique for nitrogen treatment of diesel cylinder cover

Abstract

The invention provides a nitrogen treatment technique of ship firewood cylinder sleeve, which is characterized in that a tempering working procedure is added after rough machining and semifinishing of machining before nitrogen treatment respectively. Due to the scientific control of technique parameters such as warming rate, heat insulation time, cooling rate and dissolution rate of alkaline air, the nitrogen process is under strict control so that the nitrogen deformation is small and the nitrogen layers are even. The invention has advantages that a silvered nitrogen layer evenly coated on the nitrogen-treated surface of the cylinder sleeve has a good quality of rust protection and high resistibility of cavitating corruption; after being polished a few nitrogen pocking marks are left on the nitrogen layer of inner hole, and the reticulate pattern is clear; the cylinder sleeve has a good oil-store performance, high abrasion resistibility and low engine oil consumption.

Description

Technical field [0001] The invention relates to a process for nitriding a cylinder liner of marine diesel. Background technique [0002] Due to various reasons such as the bore, workload, and cooling water quality of the diesel cylinder liner, the water jacket part of the cylinder liner is severely corroded, and cavitation failure is the main form. The industry solves this problem by nitriding the cylinder liner. However, the material of the cylinder liner is mostly gray cast iron, and the carbon content in gray cast iron is relatively high. During the nitriding process, the carbon is burned and easily forms cavities. The brittle and hard nitrides formed after nitriding It is easy to fall off during the polishing process and form pits. A large number of pits are the main reason for the oil consumption of the cylinder liner during use. Contents of the invention [0003] The invention provides a process for nitriding treatment of diesel cylinder liners. This process can not...

AI Technical Summary

Problems solved by technology

[0002] Due to various reasons such as the bore, workload, and cooling water quality of the diesel cylinder liner, the water jacket part of the cylinder liner is severely corroded, and cavitation failure is the main form. The industry solves this problem by nitriding the cylinder liner. However, the material of the cylinder liner is mostly gray cast iron, and the carbon content in gray cast iron is relatively high. During the nitriding process, the carbon is burned and easily forms cavities. The brittle and hard nitrides formed after nitriding It is easy to fall off during the polishing process and form pits. A large number of pits are the main reason for the oil consumption of the cylinder liner during use.

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