大耕深旋耕刀的制造工艺及其耐磨性

Manufacturing process and wear resistance of deep-tillage rotary blade

针对大耕深(耕深大于20cm)旋耕刀表硬心韧的性能要求,提出对旋耕刀"表面渗铬—淬火—中温回火处理"的制造新工艺(简称渗铬热处理工艺),考察了采用该工艺所制旋耕刀的室温干摩擦磨损行为,并与传统制造工艺(整体淬火—低温回火)进行了对比.结果表明:采用渗铬热处理工艺制造的旋耕刀具有典型的表硬心韧组织结构,其表层为高硬度的渗铬层,心部为高抗弯强度和韧性的回火屈氏体;在相同实验条件下,经渗铬热处理后试样的摩擦系数降低,相对磨损率仅为经传统工艺处理后试样的0.408,可较好地满足稻麦两熟作业区大耕深旋耕作业要求.

A novel rotary blade manufacturing process for quenching and medium-temperature tempering after chromizing （referred to as chromizing heat treatment process） was proposed in this work, aiming at meeting the hard-surface and tenacious-core performance requirements of rotary blade suitable for large tilling depth （over 20 cm）. The dry frictional wear behavior in room temperature of the rotary blade prepared by the chromizing heat treatment process was investigated, compared with the conventional technique （overall quenching and low-temperature tempering）. The results show that the typical hard-surface covered with high hardness chromizing layer and tena- cious-core microstructure provided with good bend strength and toughness tempered troostite are obtained after chromizing heat treatment. Moreover, under the same experimental conditions, the friction factor of the sample prepared by chromizing heat treatment process reduces and the wear rate is only 0. 408 for the one treated by the conventional technique. The rotary blade prepared by the chromizing heat treatment process can meet the requirements of deep-tilling rotary tillage in the rice-wheat cropping areas.