冲压滚针轴承的热处理技术

Heat Treatment Technology for Needle Roller Bearing

冲压滚针轴承由滚针、外圈和保持架组成,具有质量轻、成本低和转速较高等特点。其外圈和保持架材料采用含碳量仅0.006%~0.009%、厚0.63~1.5 mm的低碳或低碳低合金钢冷轧薄板冲压制成。这种滚针轴承的外圈和保持架均要进行渗碳（或碳氮共渗）和淬火处理,其冲压外圈渗层深度为0.08~0.33 mm,淬火后硬度为840~900 HV;保持架渗层深度为0.02~0.12 mm,淬火后硬度为410~550 HV。滚针材料为GCr15钢,要求淬火、回火后硬度65~66 HRC。目前,最可行的制造工艺为将外圈、滚针和保持架组装后再热处理,能确保产品质量,缩短热处理周期。

A stamped needle beating consists of needle, outer race and cage , and has the advantages of light mass, lower cost and higher rotating speed. The outer race and the cage are made of cold-rolled low-carbon or low-carbon low-alloy steel sheet 0.63 to 1.50 mm thick containing as little as 0. 006% to 0. 009% C by stamping, and must be carburized （ or nitrocarburized） to 0.08 to 0.33 mm and hardened to 840 to 900 HV for the former and to 0, 02 0.12 mm and to 410 -550 HV for the latter. In addition, the needle is made of GCrl5 steel, and required to reach as high hardness as 65 -66 HRC by hardening and tempering. At present, the most feasible manufacturing process consists in assembling the outer race, needle and cage into a whole followed by the heat treating, making it possible to ensure the bearing quality and to shorten the heat treatment cycle.