After using the weighted drill pipe of the rotary excavator for some time, we will all find that there will be different degrees of wear and tear. Of course, some wear and tear are inevitable. Because, in the use of the oil drill pipe of the rotary excavator, there is no lack of friction between the various parts and so on, it is not surprising that there is wear. However, what is the main aspects of the wear of the drill pipe of the rotary excavator? What are the wear and tear?
This is mainly related to welding level and welding process control. By tracking the welding process on-site, it is found that during the welding process, the operator uses a common electrode, and there are no specific requirements for the width of the weld and the welding method. To improve efficiency, the operator uses a thick electrode to weld only one pass. , which reduces the strength of the weld, lacks penetration and does not weld to the bottom.
1. Abrasive wear
Abrasive wear is the phenomenon of surface scratches and surface material falling off caused by external hard particles or micro-peaks on the hard surface during the relative movement of the surface of the drill pipe of the rotary drilling machine. Tears, longitudinal pull marks, local spalling, and cracks. The abrasive wear mechanism is microscopic cutting, multiple plastic deformations leading to fracture, and microfracture. Under the compound stress state, the drill string is prone to large bending, and serious friction occurs between the protruding place and the hard rock layer after bending. The thickness of the quenching treatment on the surface of the drill string is generally 1mm. After the quenching layer is worn away, the subsequent wear rate will be accelerated. In deep hole drilling, sometimes there are obvious scratches on the surface of the drill pipe taken out, which is the manifestation of abrasive wear.
2. adhesive wear
Adhesive wear is a wear phenomenon caused by the transfer of material from one surface to another surface or the material falling off from the surface due to adhesion when the surface of the anti-sulfur drill pipe of the rotary excavator slides relatively. Since the actual contact area between the surfaces is very small, the stress at the contact point is very high. The surface of the drill pipe of the rotary excavator is in such a high temperature and high-stress state, and the surface of the rod is cracked, causing the contact micro-peaks to stick, and then the sticking point during sliding. was cut off. The bending of the drill pipe causes local friction with the rock formation, and the high stress at the local contact points creates conditions for adhesive wear.
3. fatigue wear
Fatigue wear is the rolling or rolling erosion wear mechanism on the surface of the thick-walled drill pipe of the rotary excavator: in low-angle erosion, it is mainly in the form of micro-cracks and micro-cutting; in high-angle erosion, the crack propagation and brittleness are the main forms. The break is dominant. During the working process of the drill pipe string, the rotation speed is large, and the relative speed to the drilling fluid is also large. If the viscosity and weight of the drilling fluid are large, the sand content is high, and long-time drilling is Caused by erosion wear that cannot be ignored.