大型挖掘机履带行走部分的主动轮和支重轮,工作条件恶劣,磨损严重,载荷不均,常因过载使接触面压溃变形,断裂和早期磨损失效。为提高使用寿命,曾将表面淬火改为整体透烧加热,然后浸冷淬火(轮毂保护),零件质量虽有提高,但轮缘硬化层浅而不均,轮幅部分也随之淬硬,不利于孔精加工。为进一步提高使用寿命,必须增加零件的淬硬层深 The driving wheels and supporting wheels of crawler walking parts of large excavators have poor working conditions, serious wear and uneven load, and often cause contact surface deformation, fracture and early wear failure due to overload. In order to increase the service life, the surface quenching was changed to the whole thawing heating, and then the immersion quenching (wheel protection), although the quality of the parts is improved, but the rim hardened layer is uneven and the spoke part is also hardened. Not conducive to hole finishing. To further increase the service life, the hardened layer depth of the parts must be increased