Preparation Of Wear Resistant Layer By Plasma Cladding And Matching Optimization Of Its Friction Matching Pairs

Shearer boots is the key component of shearer's walking part,which requires high wear resistance and belongs to vulnerable parts.It needs to be replaced frequently.At present,many scholars have done a lot of research on the hardness and wear resistance of shearer boots.The performance of shearer boots has been greatly improved.However,the change of slot edge steel material with its matching pairs is small,and the enhancement of the performance of shearer boots often leads to the reduction of the service life of slot edge steel with its matching pairs.Therefore,it is necessary to optimize the surface modification of shearer boots from the angle of friction matching between shearer boots and matching slot edge steel,so as to improve the service life of shearer boots and matching slot edge steel at the same time.In this paper,plasma cladding technology is used to modify the surface of shearer boots material.The technological parameters of plasma cladding are optimized by metallographic analysis and hardness testing.The excellent wear-resistant cladding layer is prepared.The microstructure and phase composition of the cladding layer are analyzed.Through friction and wear experiments under various working conditions,the longest service life of friction pair between shearer boots and slot edge steel is optimized.The main conclusions are as follows:?1?Three kinds of alloy powders were selected to optimize the plasma cladding process,and the preparation parameters of the three powders were determined.The content of Cr₃C₂ in nickel-based alloy of A#,Cr₃C₂ in iron-based alloy of B#and Cr₃C₂ in iron-based alloy of C#were 18%,38%and 16%,respectively.Three kinds of wear-resistant cladding layers with uniform and fine structure and excellent properties were obtained,and the thickness was 3-5 mm.?2?Under dry friction condition,the friction coefficient of wear-resistant cladding layer decreases under high speed condition and low speed condition.Work hardening occurs during wear process.Among B#samples,Cr3C2 content is the highest,wear resistance is better,wear weight loss of B#samples is the smallest,correspondingly,the wear weight loss of slot edge steel is also the smallest.The main wear mechanism of cladding layer is abrasive wear,and the wear mechanism of slot edge steel samples is adhesion wear and abrasive wear.?3?Under corrosive wear,the lubrication effect of three corrosive liquids on friction pairs is greater than that of corrosive wear.The wear weight loss of friction pairs decreases in varying degrees compared with that under dry friction.The wear weight loss of B#specimen is the smallest under three conditions,and the corresponding wear weight loss of slot edge steel is the smallest.The wear mechanism of cladding layer specimen is mainly adhesive wear,accompanied by a small amount of corrosion wear and abrasive wear.The wear mechanism of slot edge steel specimens is adhesive wear,abrasive wear and corrosion wear.?4?Under abrasive wear,the friction coefficient curve of the friction pair increases slowly,and takes longer to reach the stable stage.The wear weight loss of B#specimen is the smallest,and the corresponding wear weight loss of slot edge steel is the smallest.The wear mechanism of cladding layer and slot edge steel specimen is abrasive wear.High friction coefficient and wear weight loss ratio,low speed dry friction condition and three corrosive wear conditions are all large.?5?Under dry friction condition,the wear weight loss of B#specimen is the smallest,and that of corresponding slot edge steel is the smallest.Under corrosive and abrasive wear conditions,the B#specimen is also the most wear-resistant,and the corresponding slot edge steel is also the least wear-resistant.The best friction and wear resistance of cladding layer and slot edge steel pair of B#specimen are obtained by comprehensive comparison.