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针阀体是柴油机精密偶件中的关键偶件,工作条件苛刻,其中孔和座面要承受反复磨擦和冲击,每分钟达550次;储油槽和高压油孔要承受高的油压力,瞬时压力可达900公斤/厘米~2;头部承受较高的热负荷,约250℃。因此,对针阀体要求,要有高的硬度和耐磨性,良好的尺寸稳定性,一定的耐热性和抗接触疲劳性能。目前我国柴油机针阀体一般选用两种材质制造,大部分选用GCr15轴承钢,采用盐浴或保护气氛加热淬火,另外还选用18Cr2Ni4WA钢,采用固体渗碳和盐浴或保护气氛加热淬
Needle valve body is a key part of diesel precision coupling, harsh working conditions, in which hole and seat to withstand repeated friction and impact, up to 550 times per minute; reservoir and high pressure oil hole to withstand high oil pressure, instantaneous Pressure up to 900 kg / cm ~ 2; head to withstand higher heat load, about 250 ℃. Therefore, the needle body requirements, have high hardness and wear resistance, good dimensional stability, a certain degree of heat resistance and contact fatigue performance. At present, China’s diesel needle body generally made of two materials, most of the selection of GCr15 bearing steel, salt bath or protective atmosphere heating quenching, the other also used 18Cr2Ni4WA steel, solid carburizing and salt bath or protective atmosphere heating quenching