| The rapid development of modernization in China has triggered tremendous traffic pressure to society in recent years,thus an inevitable wave of the underground space resources utilities is raised.Among them,as the "soul" tool of tunnel engineering,the demand for TBM(Full Face Rock Tunnel Boring Machine)is increasing,while the performance of the hob ring,the key components of TBM,cannot meet the current drilling requirements in hard rock geology.In this paper,the wear condition and mechanism of the self-made DC53 steel(DB1)in different uniaxial compressive strength rocks as friction pairs are studied.At the same time,the wear mechanism under different loads and different wear distances and the effect of the abrasive grain size on the wear resistance of DC53 steel are analyzed by comparing to H13 steel,domestic DC53 steel and imported DC53 steel.The specific experimental conclusions obtained are as follows:After the self-prepared DC53 steel is subjected to a heat treatment process,the matrix structure obtained is tempered martensite and a small amount of residual austenite,and bulk eutectic carbides and granular carbides are distributed in the matrix.The structure is uniform and has high comprehensive properties;the size of the abrasive grains and the external load have an important influence on the wear of DC53 steel.With the increase of the size of abrasive grains,the three kinds of steels exhibited a significant increase in the degree of occurrence.With the increase of the load,there is a significant difference in the amount of wear of the three steels.The form of wear is mainly micro-cutting and furrow cutting,and micro-squatting is also present.The research on the wear mechanism of DB1 steel on different rock pairs shows that when the appropriate applied load,speed and uniaxial compressive strength are selected,the wear ratio is 4.5 when the pair is ground under soft rock,the wear resistance is better,and the wear mechanism For the combined effect of micro-cutting removal and micro-fracture,the main manifestations are more furrows and more spalling pits.When facing under hard rock with uniaxial compressive strength of 200MPa,the wear ratio is 12.8,the wear resistance is poor,the wear mechanism is micro-cutting,and the main performance is the deep and wide furrow.Under the same applied load and wear distance,the wear resistance of DB1 steel is better than H13 steel,and the wear amount of DB1 steel is much lower than that of H13 steel.The wear resistance of DB1 steel is slightly worse than domestic and imported DC53 steel.The size of carbides of DB1,domestic DC53,and imported DC53 steels were 10.05μm,15.45μm,and 16.43μm,respectively,and the volume fractions were 1.81%,1.71%,and 2.09%,respectively.There were no significant carbides in H13 steel.With the increase of the amount and size of carbides,the wear of the abrasive machine changes from micro-cutting abrasive grain wear to micro-fracture-type wear.The carbide blocks the abrasive grains from furrow cutting,and spalling occurs under repeated impact. |
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