Heat Treatment Process of Rock shank adapter
The heat treatment process of the shank adapter of the rock drill is still very technical.
The heat treatment process of commonly used shanks adapter is: forging blank - stress relief annealing - machining - carburizing - quenching - low temperature tempering
Straightening - shot blasting - fine grinding.
(1) Stress-relief annealing In order to eliminate the residual stress in the forging, the pre-heat treatment of the shank adopts stress-relief annealing. Heat the embryo slowly to
Between 600~650℃, keep warm for 4~6 hours, and then cool down to room temperature with the furnace. Annealing can not only eliminate the residual stress, but also greatly reduce the strength and hardness, fine
grain
(2) Carburizing
Because the alloy structural steel of 35SiMnMoV is a dry low-carbon alloy steel, the carburizing process can be adopted. The carburizing temperature is 920+10°C.
3~9 hours, in order to make the carbon potential have a favorable comprehensive effect on the carburizing process. Furnace potential can be controlled in sections to carburize the shank
(3) Quenching
A 75Kw salt bath furnace is used, the preheating temperature before salt bath quenching is 650°C, and the holding time is 90min. The salt bath heating temperature is 880+10°C, and the heat preservation
25min. The isothermal was carried out in a smoke chamber at 270°C, and the isothermal time was 60 minutes.
Finally, temper at a low temperature to keep the center and surface temperature of the shank constant!
