Many customers in the use of shearer, digger and other machinery found that the mechanical picks are liable to malfunction, through the analysis of the investigation we get the following reasons.
1. Low impact resistance. The performance of alloy head is poor, there are uneven grain distribution, graphite impurities, and backward technology in the alloy head. The residual stress of brazing alloy head is large. The fracture and eccentric wear of the pick head caused by unstable material will cause the alloy head to lose protection support prematurely.
2. Low wear resistance. The high cobalt content, low density, incomplete structure and low hardness of the pick alloy lead to poor wear resistance of the pick alloy cutter disc.
3. Alloy head come off. Alloy head shedding is one of the main failure forms of pick. Because of poor weld quality, low strength, the processing size of the pick tooth body is not strictly controlled, leading to too large or too small weld gap, resulting in solder flow difficulties, resulting in the pick scrap in advance, resulting in machine damage. Improper brazing process of alloy head will also lead to alloy head falling off.
Diamond picks are used on round shank bit, diamond pick is mainly used in the field of roadway excavation and tunnel excavation. shearer picks can cut more hard ore and coal seam. The rotary drilling machine picks is mainly used for deep mining, which can be exploited with higher efficiency and improve work efficiency. However, the wear rate of the pick is higher, and cold cracks may occur during operation.
1.High carbon content of cutting pick. In the manufacturing process of the pick, alloying elements enhance the relative hardening capacity.
2. Poor welding process. Hydrogen element exists in the weld seam during welding and does not diffuse in time, so that hydrogen element collects in the metal and produces large stress, which will lead to cold crack.
3.The thickness of the pick welding parts is not up to standard, and the stiffness of the welding parts is large, which increases the welding joint force.
4. Picks are not heated and cooled evenly in the welding process, so picks are prone to cold cracks.
----EDITOR: Anna Wang/Doris Hu
-----POST: Doris Hu