The Study On Failure Analysis CMM25-4 Four-armanchor Jumbo Bit Base Guide Plate And Wearing Resistance Of Selected Material

CMM25-4-type four-arm base Anchor Drill Bit guide plate which is made by Coal Science Research Institute, Shanxi Coal Mine Mechanical Equipment Co. Ltd doesn't meet design requirements for wear resistance when used, which affects the normal operation of equipment.In this paper, after studying composition, metallurgical structure, friction condition and abrasion of applied guide plate, we find serious abrasive wear has happened to applied material because of inappropriate composition of guide plate. The mechanical properties, especially hardness, lead to lower wearing resistance. Meanwhile, it works under harsh condition (insufficient lubrication).Both above cause failure of the guide plate. So we substitute common materials whose strength and hardness are between applied material and HG70 steel for applied material.Base on considerable papers and standards, considering real working condition of CMM25-4-type four-arm base Anchor Drill, we choose ZCuZn40Pb2,QSn7-0.2,QSn10-land QA110-4-4 among three kinds of typical Cu (brass, tin bronze, aluminium bronze) alloys for our experiment and compare them with applied material of guide plate and designed material of guide plate.In this paper, we research mechanical properties, especially wearing resistance systematically.Considering metallurgical structure, SEM imagine, we choose material with exceptional wearing resistance to replace of applied material as guide plate.The results indicate under simulated condition, top 2 among the five items in experiment are QSn7-0.2 and QSn10-1, wearing resistance of QSn7-0.2 and QSn10-1 is as 2.2 and 1.9 times as applied material respectively. Both of them can meet requirement. According to variable load experiment and variable speed experiment, QSn7-0.2 is fit for work under light load condition at moderate speed. Under this condition, the wearing capacity of QSn7-0.2 is small. QSn10-1 is fit for work under heavy load (such as 4.7Mpa-0.23m/s)condition at low speed. Based on difference between two kinds of materials, we decide to replace QSn7-0.2 of applied material ultimately.The problem insufficient wearing resistance of applied material of guide Plate used in CMM25-4-type four-arm base Anchor Drill has been resolved successfully. It is very significant to decrease failure of abrasive wear in coal mine machine.