Worm is a significant piece of machine instrument turning parts. Worm twisting surface and worm gear tooth surface slip moderately while working, which is not difficult to wear. In this way, the worm will ordinarily carburizing extinguishing treatment to acquire higher hardness to forestall worm winding surface wear. Worm parts require high accuracy, so the handling innovation is perplexing and long. Assuming there is any issue during handling, it will cause huge misfortune. A sort of worm parts in our organization seemed crushing breaks during crushing, bringing about parts rejected, genuinely influencing the creation plan.
1. Worm material and principal process stream
The worm material is 20CrMnTiH and the intensity therapy requires carburizing and extinguishing with a profundity of 1.1-1.5mm and a surface hardness of 58HRC in the wake of extinguishing.
Blanking→Forging→Normalizing→Rough machining→Stress relieve→Fine machining→carburizing→Carbon eliminate on the thread→Quenching→Rough grinding→Test→Aging→Fine crushing
Heat treatment process: Producing normalizing→ Carburizing →Quenching →Low temperature treating →Straightening→Stress relief→Low temperature maturing.
Subsequent to carburizing and extinguishing, the carburized profundity layer is 1.32mm and the surface hardness is 59 to 60HRC.
2. Break peculiarity portrayal
After harsh crushing, the break shows up on the tooth surface of the worm. The breaks are extremely fine, straight and shallow top to bottom. The Precision Grinding Wheels state of the breaks is typically called “hairline”. The breaks are not equal and dispersing lines.
3. Investigation of crushing breaks
It is clearly not quite the same as normal extinguishing breaks. The extinguishing breaks are thick and profound, and the quantity of breaks is little. It just happens on the crushing surface, and the number is enormous, the profundity is shallow, yet the profundity is fundamentally something very similar. The lighter ones are stripe breaks opposite to or almost opposite to the crushing heading. The worm tooth surface is a twisting surface.