Ground source heat pump well drilling wear-resistance bit and manufacturing method thereof

Abstract

The invention discloses a ground source heat pump well drilling wear-resistance bit and a manufacturing method thereof. The manufacturing method is characterized by comprising the following steps: uniformly mixing tungsten carbide powder and nickel base alloy powder according to a weight ratio of 3:10-60, adding rosin-containing turpentine oil serving as a bonding agent into the mixture in an amount of 3 to 10 percent of the weight of the powder to make slurry through stirring, and coating the slurry on a damageable working face of a steel blank of the bit to form a 1.3 to 6.5 millimeter coating; and drying the bit in an oven at a temperature of between 80 and 160 DEG C for 1 to 3 hours, heating the bit at a vacuum of 10 to 30 Pa to 1,080 to 1,180 DEG C for vacuum melting, keeping the temperature for 30 to 55 minutes, furnace cooling the bit to 260 DEG C, and tapping air cooling the bit to obtain ground source heat pump well drilling wear-resistance bit of which the working face of the steel blank is melt with 1 to 5 millimeter nickel-base carbon tungsten alloy. The bit has the advantages of a damageable working face hardness of HRC58-71, excellent plasticity, low manufacturing cost, service life which is 3 to 5 times that of the prior roller bit and easy damaged working face repair.

Description

technical field [0001] The invention belongs to the technical field of drill bits, and in particular relates to a wear-resistant drill bit suitable for ground source heat pump drilling and a vacuum welding technology for obtaining a nickel-based tungsten carbide alloy wear-resistant layer on the surface of a steel base. Background technique [0002] Ground source heat pump technology is a new type of energy-saving technology that uses underground shallow renewable energy as a low-temperature heat source to cool or heat buildings. About 1 / 3 of the projects are drilling projects, and the loss of drill bits accounts for about 15% of the cost of drilling projects. Therefore, improving the service life of the drill bit and reducing the manufacturing cost of the drill bit are an important part of popularizing and using this energy-saving technology. At present, the drill bits used at home and abroad are basically roller cone bits or composite drill bits for geological drilling. Th...

AI Technical Summary

Problems solved by technology

At present, the drill bits used at home and abroad are basically roller cone bits or composite drill bits for geological drilling. This type of drill bit is composed of a steel blank and a wear-resistant layer on the working face. The wear-resistant layer on the working face is generally welded by silver welding. Diamond is welded to the steel blank. This kind of drill bit has better performance and longer service life when used in stable formation properties; but its disadvantage is that it is fragile when encountering hard objects, and it is not easy to repair, and the cost is high.

The drilling depth of ground source heat pumps is generally about 100 meters, and the number of wells required is large. A project often requires drilling hundreds of wells, and most of the drilling conditions are soil or weathered layers, which often contain pebbles, construction waste, Uncertain hard objects such as scrap steel, when the drill bit using diamond as the working face is used in such soil or regolith containing uncertain hard objects, it is easy to collapse when it encounters hard objects, and the damage frequency is high; it is not easy to repair after damage , high cost, low efficiency

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