材料期刊网

目的 提高2011型除雪车滚刷焊接齿轮的综合力学性能和镀锌层质量.方法 热处理前齿面预留0.4 mm的磨削量,硬度调质到230~270 HBW.焊接完成后,立即在井式炉中消除焊接产生的热应力,900℃高温入炉快速加热,860℃保温淬火,并及时回火.该焊接齿轮的电镀工艺分为预处理、活化、电镀、钝化和烘干五个步骤,采用亚苄基丙酮作为主光亮剂的新型镀锌溶液进行电镀.结果 焊接齿轮进行整体调质热处理后,焊缝区组织主要是细小均匀的回火索氏体,力学性能优良稳定,避免了HAZ区的软化、脆化、硬化,预堆低碳钢后综合力学性能最好,按此工艺生产的齿轮经检测全部合格.焊接齿轮电镀层主要成分为Zn,少部分为Fe,Zn的质量分数沿着基体金属向镀层方向递增,而Fe递减.电镀层的厚度约为6~8μm,镀锌层与基体附着紧密,镀层无粗糙、起泡、裂纹、孔隙或局部无镀层的情况.结论 焊接齿轮齿面预留磨削量,采用最小变形热处理工艺,确保了尺寸精度,降低了加工难度,利于批量多规格工件的生产.采用堆焊过渡层焊后调质工艺,可显著提高焊接齿轮的焊缝区域的综合力学性能.对焊接齿轮镀锌层进行国标检验的结果 表明,本文采用的镀锌溶液配方和电镀工艺效果良好,电镀层厚度均匀,分布合理,致密度、附着力良好,耐腐蚀性优良,具有较大的推广应用价值.

Objective To improve the comprehensive mechanical properties and zinc coating qualities of 2011-snow remover rolling brush welding gear. Methods Before Heat Treatment, the 0. 4 mm Grinding length was reserved and the hardness was quenched and tempered to 230~270HBW. After welding, the heat stress was eliminated in the well type furnace at once by fast heating at 900 ℃ in furnace, quenching at 860 ℃, and tempering in time. The electroplating process was divided into five steps, pretreatment, activation, electroplating, passivation and drying. The new Zinc plating solution was used to electroplate. Results After quenched-tempered heat treatment, the weld area structure of Welding Gear was mainly composed of small and uniform tem-pered sorbite, which led to the excellent and stable mechanical properties, and the softening,embrittlement,and hardening of the HAZ zone were avoided. The gears which were processed and manufactured by means of pre-stack low carbon steel showed the best comprehensive mechanical performance and were tested to be qualified. The main component of the coating was Zn, and there was a small part of Fe. The mass fraction of Zn increased along the base metal to the coating, and Fe showed the opposite trend. The thickness of the plating layer was about 6 ~8 μm,and the zinc coating was closely attached to the gear. The coating showed no roughness, foaming, cracks, porosity or local uncoated situations. Conclusion The minimum deformation heat treatment process was used for gear welding, which ensured the dimensional accuracy, reduced the processing difficulty, and was conducive to the production of the workpieces. The mechanical performances of weld area were significantly improved by the process of bead welding transition layer. The national standard test showed that the electroplated coating had uniform thickness, reasonable distribution, good density, adhesion and corrosion resistance. The zinc plating solution and electroplating process of this paper had a great value of popularization and application.