1.前言 L.R.S.最近对船用燃油进行分析,油中的硫占4％,钒为437ppm。燃用这种油时,温度较高的部位容易发生高温腐蚀,而温度较低的部位发生硫酸腐蚀,影响船用柴油机的耐久性和可靠性。特别是排气门,高温腐蚀加剧了漏气烧损。日本钢管公司为提高船用柴油机的耐久性和可靠性,从1980年起开始研制陶瓷排气门。目标是实现气门锥面陶瓷化(陶瓷排气 1. Introduction L.R.S. recently analyzed marine fuels with 4% sulfur in the oil and 437 ppm vanadium. Burning this oil, high temperature parts prone to high temperature corrosion, and sulfuric acid corrosion occurred at lower temperatures, affecting the durability and reliability of marine diesel engines. Especially the exhaust valve, high temperature corrosion exacerbated air leakage loss. Japanese steel pipe companies to improve the durability and reliability of marine diesel engines, from 1980 onwards to develop ceramic exhaust valve. The goal is to achieve the valve cone ceramic (ceramic exhaust