论文部分内容阅读
为了适应增压、高速、大马力柴油机的性能要求,排气门在800℃高温下工作时,要有足够的高温强度,硬度,抗氧化与抗硫化物腐蚀的性能。用21—4N合金或21—2N合金作排气门,就需要在阀面上堆焊钴基的钨铬钴合金（STELLITE6或STELLITEF）来改善抗腐蚀性。 1978年前后,钴的价格暴涨,并且不能正常供应。汽车制造商以镍基合金INCONEL
In order to meet the performance requirements of supercharged, high speed and high horsepower diesel engines, the exhaust valve should have sufficient high temperature strength, hardness, oxidation resistance and sulfide corrosion resistance when it is operated at a temperature of 800 ° C. Using a 21-4N alloy or 21-2N alloy as the exhaust valve requires a cobalt-based stellite (STELLITE 6 or STELLITEF) to be deposited on the valve surface to improve corrosion resistance. Before and after 1978, the price of cobalt soared and could not be supplied normally. Car manufacturers to nickel-based alloy INCONEL