Study on Improving Wear Resistance of Cutting Tooth and Cutting Head of Roadheader
时间：2019-09-30作者： baidu baike 阅读量：
With the development of roadheader toward heavy and hard rock, the requirement for wear resistance of cutting teeth is more and more stringent. Now the wear resistance and cost performance of cutting teeth are far from meeting the expectations of users, which requires the manufacturers of roadheader to develop high cost performance cutting teeth suitable for hard rock. It can be predicted that the wear resistance of pick will become the main bottleneck of this type of machine. According to statistics, the wear resistance and cost-effectiveness of the heavy-duty whole-rock roadheader, which has been used in China and abroad, are unsatisfactory. The wear of the cutting head is also very serious. The cutting efficiency and production cost are basically the same as that of blasting mining. But because of the high safety of roadheader and the small damage to roadway structure, coal mine must be used, and the number of use is increasing year by year. The damage of the pick is not only the damage of the pick itself, but also the damage of the corresponding pick base after the damage of the pick, which makes the cutting head not in normal use, and the characteristics that the underground can not be welded make maintenance very difficult.
1, current situation
There are two main types of cemented carbide head, one is cylindrical (Fig. 1). The wear pattern of the cemented carbide head is that the base of the pick enclosing the alloy head is worn out, which results in the force shedding of the alloy head, and the wear of the alloy head is very little, which is a great waste.
This kind of pick is mainly because the alloy head can not protect the tooth body well, and the metal wear resistance of the tooth body is poor, which leads to the damage of the pick (Fig. 2); the other is the mushroom type (Fig. 3), whose wear pattern is also the wear of the matrix enclosing the alloy, resulting in the alloy head falling off. Because this alloy head has a specific protective effect on the metal of the tooth body, the use of this kind of pick The life of the alloy head is longer, but the quality of the alloy head is difficult to guarantee, because it often occurs alloy fragmentation when cutting hard rock. The pick represented by Kenamat products is this type. The quality of the alloy head abroad is better, and it is difficult to guarantee the effect of domestic use.
2. Improvement method
In view of the advantages and disadvantages of the two kinds of pick mentioned above, two methods are proposed to test whether the service life of the pick can be improved.
(1) Soldering a wear-resistant layer on the outer surface of the upper teeth of the pick as shown in Fig. 1 (Fig. 5). The wear-resistant layer can greatly improve the wear resistance of the tooth body and the service life of the pick. At the same time, the wear-resistant layer can be added before the brazing alloy head, and the heat treatment of the tooth body has no effect on it. Because of melting welding, the wear-resistant layer will not fall off. This kind of wear-resistant metal similar material I have done a simple test, high hardness, no Mars with angular friction, is 8-15 times the service life of ordinary steel plate, wear resistance is very good, this wear-resistant layer has been widely used in metallurgy, mining, power and other industries. This method has been communicated with the relevant manufacturers, because of its good operability, the method is feasible.
(2) At present, there is a kind of pick which is surfacing wear-resistant electrode on the external surface of the pick, but because it is only surfacing on the surface of the pick body, the alloy head and the joint of the tooth body are still wearing fast. If there is a kind of wear-resistant electrode which can be welded well with the alloy head, this problem will be solved. German Faudi Company is the ancestor of German wear-resistant electrode. Its company has a kind of wear-resistant electrode. Its electrode base is tungsten and cobalt alloy, which is similar to the alloy head material. It can weld well with the alloy head, so that the wear-resistant electrode can be welded with the alloy head and the tooth body, so as to protect the tooth body.
3 concluding remarks
The damage of the pick is not only the damage of the pick itself, but also the damage of the corresponding pick base after the damage of the pick, which makes the cutting head not in normal use, and the characteristics that the underground can not be welded make maintenance very difficult. Therefore, it is very important to carry out the related research work of the pick, which is the foundation of the development of the roadheader industry.