论文部分内容阅读
渗碳、碳氮共渗淬火另件,必须按规定的标准工艺进行退火获得平衡状态的组织方能测定渗层的深度。“ ISO”标准以显微硬度法测定,但目前国内大多数机械构件的渗层测定仍采用金相法。常用渗碳、碳氮共渗的20Cr、20CrMo、20CrMoTi等材料制成的另件,国家（或部级）标准中均规定了相应的退火工艺。目的在于获得处于平衡或接近平衡状态的退火组织、通过显微组织的鉴别来测定渗层的深度。例如: 渗碳活塞销, 1984年9月机械工业部颁布的渗碳活塞销金相检验标准规定: 850℃加热15～20分钟,650℃等温10～20分钟空冷。 检验实践证明,按上述工艺处理20CrMnTi、20Cr、20CrMo等材料一般是可以得到平衡或接近平衡状态的组织,但有诸多的弊端。首先需备有两台炉子作为加热设备,工艺较复
Carburizing, carbonitriding quenching the other pieces, must be annealed according to the provisions of the standard process to obtain an equilibrium state of the organization can measure the depth of the layer. The “ISO” standard is determined by the microhardness test. However, the most commonly used method for the determination of the permeation layer of mechanical components in China still adopts the metallographic method. Commonly used carburizing, carbonitriding 20Cr, 20CrMo, 20CrMoTi and other materials made of other pieces, the national (or ministerial) standards are provided in the corresponding annealing process. The aim is to obtain an annealed tissue that is in or near equilibrium and to determine the depth of the layer by microscopic identification. For example: carburizing piston pin, September 1984 issued by the Ministry of Machinery Industry carburizing piston pin gold phase inspection standards: 850 ℃ heating 15 to 20 minutes, 650 ℃ isothermal 10 to 20 minutes air-cooled. Test proved that, according to the above process 20CrMnTi, 20Cr, 20CrMo and other materials are generally balanced or near-equilibrium organization, but there are many drawbacks. First of all, two furnaces are required as a heating device, and the process is complex