I. Classification of rock drilling tools and engineering drilling tools
According to the action principle of rock drilling tools when breaking rock, rock drilling can be divided into:
1. Impact drilling,
2. Rotary cutting,
3. Rotary crushing,
4. Rotary grinding, etc.
According to the design structure and applied characteristics of drilling tools, rock drilling tools can be divided into:
1. Top hammer rock drilling tools,
2. Down-the-hole rock drilling tools,
3. Mining tricone rock drills Tools,
4. Reverse patio rock drilling tools,
5. Mechanical cutting (including TBM) and pavement milling planer tools,
6. Geological exploration drilling tools, etc.
II. At present, the output value of ourcountry’s main brazing steel products
By the end of 2016, the output value of China’s drill steel and drilling tools industry (excluding hollow steel, geological cemented carbide, and steel for rock drilling tools) was about 8 billion yuan, and the proportions of its product categories are roughly as follows:
1. Drilling tools for light rock drilling machinery (H22mm tapered connection rod, D38-42mm diameter single chisel、button-shaped tapered connection drill bit, H19mm tapered connection rod, D32-36mm diameter tapered connection bit, integral Drill rod, etc.) about 25%.
2. Drilling tools for pneumatic rail rock drills ( R32 metric thread 1.1m、1.2m extension rod, thread connection light extension rod, D48-60mm diameter cross-shaped, button-shaped thread connection bit, connecting sleeve, guide rail pneumatic rock drill shank, etc.) about 0.8%.
3. Drilling tools for hydraulic rock drills (excavatordrill rods, underground mining drill rods, open-air rock drill rods, threaded connection button bits, hydraulic rock drill tails, connecting sleeves, etc.) about 8%.
4. Low and high air pressure down-the-hole drilling tools (low and high air pressure hammerand down-the-hole drill bits, drill pipes) are about 22%.
5. Tricone drilling toolsfor miningand drilling tools for patio rigs (D250mm, D310mm diameter mining tricone bits, patio drill bits, roulettes, drill pipes, etc.) are about 8%.
6. Drilling tools for metallurgical furnaces (drill pipes, drill bits, connectionsleeves, drill shanks, etc.) are about 6%.
7. Various pick drilling tools (pickers for coal mining machines, picks for engineering rotary drilling rigs, picks for pavement and municipal engineering machinery, picks for large-scale open-pit excavation machinery, picks for trench excavation machinery, etc.) about 20 %.
8. Drilling tools for shield machines and trenchless drilling rigs (disc hobs, tooth hobs, scrapers, etc.) are about 8%.
9. About 1.5% of other types of drilling tools.
Note: The statistical output value includes the output of enterprises other than Rock drilling steel and tools branch of China steel structure association.
III. Raw materials for our country’s brazing steel and drilling tools industry
In terms of raw materials used in drill products, the domestic production of various hollow steel products is about 120,000-130,000 tons each year, with a market value of about 1.2 billion yuan.
Cemented carbide enterprises produce about 9,500-10,000 tons of tungsten carbide for various geological and mineral types (including tungsten carbide alloys for recycled mining), with a market value of nearly 4 billion yuan.
Manufacturers of drilling steel and tools consume various types of steel each year, which are about 18 ten thousand tons with a market value of nearly 1.3 billion yuan.
Annual consumption of raw materials: 1.2 billion + 4 billion + 1.3 billion = 6.5 billion.
The total annual output value of brazing steel and drilling tools is 8 billion – 6.5 billion = 15 billion (gross profit)
(usually we say: the output value of drilling tools is 8 billion + the output value of raw materials is 6.5 billion, and the industrial output value involved in the brazing steel and drilling tools industry is about 15 billion. )
IV. Main types of drilling tools in our country
At present, there are nearly 200 manufacturers in the domestic drilling steel and tools industry, mainly small enterprises. The main products produced are:
1. Hollow steel for rock drilling,
2. Drilling tools for light rock drills,
3. Drilling tools for hydraulic rock drill rigs,
4. Drilling tools for down-the-hole rigs,
5. Tricone drilling tools for mining,
6. For metallurgical furnaces Drilling tools,
7. various pick drilling tools,
8. various shield machine tools, etc., a total of eight series of drilling tool products.
4.1 Hollow steel products for rock drilling
4.1.1 Hollow steel for light rock drill rod
Specification: H19mm,H22mm,a small qty of H25mm,A small amount of diamond hollow steel
Material: 55SiMnMo, 40SiMnCrNiMo ( Z708 ),95CrMo55-60Si2Mn
Capacity: about 8-10（ten thousand )tons/year
4.1.2 Hollow steel for extension rod of guide rail pneumatic rock drill
Specification: D32mm
Material: 35SiMnMoV,55SiMnMo,20CrMnTi, etc.
Capacity: about 2000 tons/ year
4.1.3 Hollow steel for hydraulic drill rod
Specification: H28mm,H32mm,D32mm,H35mm,D38mm,D45mm,D51mm,D56mm,D60mm,64mm.
Material: 20 – 22CrNi3Mo,24SiMnNi2CrMo( FF-710)
Capacity: about 8000-9000 tons/year
4.1.4 Hollow steel for metallurgical furnace drilling tools
Specification: D32,D38,D45
Material: 45#,42Mn 55SiMnMo,other alloy structural steel
Capacity: the output of hollow steel enterprises is about 7000-7500 tons/year. Among them, the largest number of hollow steel is that of diameter D38mm.
In addition, some domestic steel pipe manufacturers supply D38 diameter thick-walled pipes, the quantity is unknown.
At present, there are more than ten hollow steel manufacturing enterprises in China, of which: 5 enterprises use mechanical drilling-hot rolling with core. The raw material is 150mm billet and the length is 1500-2500mm. The domestic deep hole drilling machine is used for drilling. Among them, 3 enterprises use semi-continuous rolling mills, and the other two use horizontal rolling mills.
The remaining 5 enterprises use two-roll (three-roll) thermal piercing, three-roll reduction, and six-roll stand hot rolling (hot drawing) method. The raw material adopts D=55-90mm round steel bar.
Two of these hollow steel enterprises have steelmaking capability.
Hot piercing – hot rolled (drawn) hollow steel production line.
V. Production volume of main drilling tools in our country
5.1 Output of Drilling Tools for Light Rock Drilling Machinery
H22mm tapered connection drill rod. The current annual output is 80,000 tons/year, equivalent to 13 million pieces.
D38-42mm tapered connected in-line slice drill bit, about ~23 million pcs/year.
32-42mm tapered connection button bit ~ 11 million pcs/year.
Our views on the product problems and development trends of drilling tools for light rock drilling machines are:
Drilling tools for light-duty rock drilling machinery are currently the main domestic drilling tool products. The quality of the service life fluctuates greatly. Although it will still be the main drilling tool for tunnel construction in the future period. However, with the increase in labor costs and the strengthening of construction efficiency requirements, the use of this product will decrease year by year.
The output power of air-leg rock drills used in tunnels and underground metal mines will increase, and the requirements for the stability of the use of drilling tools will increase. The proportion of button bits in light drill bits will increase.
The market demand for high-quality drill rods (23CrNi3Mo material H22mm drill rods) will increase at home and abroad. Two suggestions are put forward for companies that produce drilling tools for light rock drilling machinery:
1. Domestic companies that produce taperedconnectionrods should pay attention to the selection of hydraulic forging and brazing machines. It is best to choose a hydraulic forging and brazing machine with dual-cylinder compression, high extrusion power, high centering performance, and high strength and rigidity. It is ensured that there is no forging defect in the shoulder part, and no deviation of the axis of the shank of the shank and the axis of the drill rod body.
2. The domestic and international market demand for taperedconnection button bits, especially high-quality products, will increase. Now many manufacturers producethis product industry too rough, especially the fixed tooth technology, enterprises with conditions should gradually adopt the hot embedded tooth technology.
5.2 D32 extension rod for guide rail mining bench
At present, a considerable part of our country’s underground mine drilling tools for mining blast holes are D32-R32 metric thread length 1.1M, 1.2M extension drill, dia. 60mm ball five-tooth drill bit, connecting sleeve, and YYG90 drill bit.
The D32 extension rod is mainly used for drilling blast holes in underground metal mines. Use R32 metric thread connecting rod to drill, usually the drilling depth is 20-25 meters. At present, domestic drill tool enterprises produce 280,000-300,000 pieces of R32 metric threaded connection rods, nearly 80,000 pieces of D60mm diameter R32 metric threaded button bits, and about 14,000 shanks for YYG90 independent rotary guide type drilling rigs.
The 35SiMnMoV and 55SiMnMo steel used in drill pipes and shank tails can meet the requirements of drilling rigs.
This kind of drilling tool can only be used in domestic underground metal mines. With the limited production of some mines and the depletion of resources, the market demand may show a slow downward trend in the next period of time.
It is hoped that enterprises that produce this product will pay attention to the processing of R32 threads, improve the matching accuracy of the casing, and relatively balance the powder discharge grooves of the drill bit to ensure the straightness of the drilling.
VI. Drilling tools for hydraulic rock drilling rigs
The main types of hydraulic drill rigs are:
a. Drill rods and drill bits for underground tunneling drill rigs.
b. Drill rods and drill bits for underground mining rigs.
c. Drill rods and drill bits for outdoors rock drill rigs.
At present, the domestic drilling tool enterprises produce about 2.1 million drill bits each year, among them:
a. The drill rods and bits of the underground tunneling drill car account for about 30% and 35% respectively (because the drill car is not used in the construction of highway and railway tunnels in China, the drill rod is about 1/2, and the drill bit is about 2/3 foreign market).
b. Drill rods and bits for underground mining rigs account for about 10% and 15% respectively.
c. Drill rods and bits for open-pit rock drilling rigs account for about 60% and 50% respectively.
In addition, domestic drilling tool companies also produce about 80,000 shanks of various types of hydraulic rock drills and more than 60,000 connecting sleeves every year.
6.1 Drilling tools for hydraulic tunneling rigs
The main products are R38/T38–H35–R32, L=3090mm, 3700mm, 4300mm, 5525mm tunneling drill rods and D45mm, 48mm diameter threaded connection button bit.
We believe that the current status and development trend of drilling tools for drilling rigs in the future are:
As labor costs increase, safety measures are regulated, and domestic companies producing underground drilling rigs increase, the domestic demand of tunneling rigs will increase.
The quality of hollow steel and heat treatment equipment are one of the important factors that affect the quality of tunneling drill rods. There are many problems in the design of the working face of the drilling bit and the structure of the powder discharge slot, the machining accuracy of the bit body tooth hole, and the method of fixing the tooth.
6.2 Drilling tools for underground hydraulic mining rigs
Drilling tools of well hydraulic mining rigs
At present, the fully hydraulic mining rigs used in large-scale underground metal mines in China are mainly Simba1254/1354 underground mining rigs produced by Atlas.Copco of Sweden. The drill rig adopts, COP1638 or COP1838HE series hydraulic rock drills, using T38, T45 threads, MF extension rods with length of 1530mm, 1830mm or mining drill rods, and D76mm, 89mm diameter threaded connection button drill bits. The varieties of underground mining drill tools mainly include:T38-D39-T38X1220mm, T45-D46 -T45X1525mm, MF drill rod, tubular guide drill rod, D64/D76/D89mm button bits.
Development Trend of Drilling Tools for Underground Mining Drill Machines:
1. To further strengthen the exploitation of underground metal mining resources is the development trend of domestic large-scale mines. The use of underground mining rigs will increase. If domestic drilling rig manufacturers can make progress in the manufacture of underground drilling rigs and underground hydraulic rock drills, this development trend will accelerate.
2. The raw materials (hollow steel, cemented carbide) used for manufacturing underground mining drill tools, MF drill forging equipment, heat treatment equipment, perforation processing equipment, processing accuracy, tooth fixation technology, etc. have many contents that need to be improved.
6.3 Drilling tools for open-air hydraulic rock drill rigs
Open-pit hydraulic rock drilling rigs are mechanized rock drilling equipment that is used more frequently in domestic projects. The open-pit hydraulic rock drilling rigs being used in construction projects of hydropower, mining, mining, and quarrying are mainly Swedish Atlas Copco Company, Sand-vik Tamrock Company, and Japan Furukawa (Furukawa).
Compared with underground hydraulic drill rigs, open-pit hydraulic rigs have simpler performance requirements as well as wider range of sites. Various domestic construction machinery manufacturers have begun to pay attention to the production of multi-functional products, the use of various types of surface hydraulic drilling rigs will increase. The demand for products will also increase.
6.4 Analysis of the development trend of hydraulic drill rods
The crawler-type single-arm drill rig produced by the company.
When the construction unit purchse the new equipment, they will dispose the old type of drill rig that was originally to the private owner of the contracted project. The latter would be applied to the construction site in large quantities after refurbishment and repairs.
In addition, at the construction site, especially the foundation engineering excavation, site leveling blasting and other construction sites, there are also a large number of hydraulic chisels used by hydraulic excavators with drill arms, equipped with various types of hydraulic chisel, and modified. Rock drilling rig. It is estimated that the number of various types of open-pit hydraulic rock drilling rigs used in China is at least 5,000.
T38, T45, T51 threads, 3050mm 3660mm MF extension rods and connecting sleeves used in open-air hydraulic drilling rigs to connect rock extension rods, as well as D76mm, D89mm and 102mm diameter threaded connection button bits are required in the drilling tool market Larger products.
It can be considered that the market demand for hydraulic drilling tools will be in a long-term upward trend. Before 2013, there were only four enterprises producing drill rods in my country. In recent years, many drill tool factories have purchased equipment and added personnel to the production of drill rods. At present, more than ten enterprises have the qualification to produce drill rods. In addition, there are more than 20 domestic enterprises producing hydraulic drill bits.
At present, the main problem of domestic drilling tools is unstable quality and relatively low service life compared with foreign products. Regarding its existing problems, it is believed that the following aspects can be advanced:
The rock drill rod is used to transfer the energy of the hydraulic rock drill to break the rock under the conditions of impact, torsion, abrasion, and water corrosion. The working conditions are very extreme. Only on the basis of high-quality hollow steel guarantee, strict production process specifications can be formulated to produce high-quality drill rods.
Hollow steel for drill rods has high requirements on material properties, and the smelting process must strictly control various chemical and metal physical properties. In the rolling process, the deformation mechanism and geometry of the steel must be controlled.
Correctly select the forging (MF, tunneling drill rod), thread processing equipment and thread structure (SR), carburizing heat treatment furnace, cooling tower, tempering furnace, carbon control/temperature control instrument, etc. in the process of brazing.
At present, the domestically produced hydraulic drill bits can be divided into the following three types according to the different places of use:
1. Tunneling bits (D45mm, D48mm), because they are mostly used in large underground metal mines or export,
2. Mining drill bits (D64, D76, D89mm) are mostly used in large underground metal mines or export,
3. Open-pit rock drill bit (D89, D02mm), mostly used in infrastructure projects, stone and cement mines, hydropower projects and other sites.
After many years of statistics on the production volume of screw-connected button ball heads for hydraulic rock drill rigs of domestic drilling tool manufacturers, it is shown that domestic drilling tool companies produce about 2.1 million drill bits of various types each year. Among them, about 35% of drill bits are used for hydraulic tunneling rigs, about 15% are used for hydraulic underground mining rigs, and the rest are basically drill bits for open-pit hydraulic rock drill rigs.
Due to the small diameter of the drill bit for hydraulic tunneling rigs, the main rock objects drilled by the drill bit for hydraulic underground mining rigs are metal veins. Therefore, as of the high requirement of the wear resistance of the drill bit shell steel and alloy teeth, fatigue crack damage resistance, and the performance of alloy fixed teeth, manufacturers are more cautious in choosing the types of shell steel and alloy teeth, and mostly use materials with better performance indicators. In terms of fixed teeth technology, hot embedded teeth are basically used.
Open-pit hydraulic rock drilling rigs are widely used, including infrastructure excavation engineering, hydropower engineering, stone mining, building materials and cement mines, as well as construction site leveling and anchor hole drilling, etc., since the nature of the rock or soil being drilled Different, the advantages and disadvantages of drill bit products are not easy to highlight, so the quality requirements for drill bits are not as strict as the first two types of drill bits. Therefore, in order to control production costs, production companies have differences in the selection of raw materials and the process of fixing teeth.
Due to the harsh stress conditions when drilling rig bits, especially for tunneling rig bits, mining rig bits, and drill bits for open-pit drill rigs produced in Sweden, it is better to use medium carbon Cr-Ni-Mo steel and Good quality alloy button teeth, using high rigidity machining center to drill the tooth holes, special measuring tools to measure the tooth holes, vacuum heat treatment furnace quenching/tempering, hot embedded tooth technology, tooth fixation, shot peening strengthening, etc. which are the same as those of foreign drill tool factories Materials and processes. It is necessary to strengthen the analysis and research of tooth surface layout, flushing hole position, and powder discharge groove shape. The production site must ensure that there are various testing and measuring tools. Enterprises that produce drill bits are better to use hot-inserted tooth technology.
VII. Drilling tools for down-the-hole drilling rigs
Among the types of products produced by domestic drilling tool enterprises, in addition to light-duty drilling tools for rock drilling machines, the products with greater market demand and rapid development are the drilling tools for down-the-hole drilling rigs. At present, there are more than 40 enterprises producing high and low wind pressure down-the-hole drilling tools in China. A production scale with an annual output of nearly 300,000 high-pressure and low-pressure impactors, nearly 4 million high-, medium-, and low-pressure DTH drill bits, and thousands of drill rigs (drill racks) has been formed. The annual output value (excluding Drilling rigs and drill stands) reached approximately RMB 2 billion.
7.1 Drilling tools for low-pressure down-the-hole drilling rigs
At present, the annual output value of low-pressure down-the-hole drilling tools produced in our country accounts for about 30% of the total one of down-the-hole drilling tools. The production enterprises are mainly concentrated in Hubei, Zhejiang, Shandong, Hebei, Fujian, Liaoning and other places. It is a product with fierce price competition in the market.
Well-known foreign drilling tool manufacturers adopt hot-insertion technology for all the fixed teeth of the drill bit for hydraulic rock drill rigs.
Support type low wind pressure down-the-hole drill and down-the-hole drill bit.
7.2 High-pressure down-the-hole drilling tools
In recent years, with the increase in sales of high-pressure down-the-hole drilling tools in the market, the number of domestic drilling tools industry turning to high-pressure down-the-hole drilling tools production is also increasing. The annual output value of the products in the total output value of down-the-hole drilling tools is around 60%, and it is still showing an increasing trend year by year. Because high-pressure down-the-hole drilling tools are more stringent than low-pressure down-the-hole drilling tools in terms of product raw material selection, mechanical processing and heat treatment technology, corporate staff quality, production site and production equipment, product processing accuracy and quality control requirements, therefore, the current domestic production areas are mainly concentrated in Hunan, Hubei, Hebei, Zhejiang, Shandong, Jiangsu, and Fujian and other places with a batch of enterprises with a proper production scale.
7.3 Status and development trend of down-the-hole drilling rigs
Our country is the main producer of down-the-hole drilling tools. The products have certain competitiveness in domestic and foreign markets. It is necessary to attach importance to the establishment of a sales technical service team and establish a product brand concept.
The fields of use of down-the-hole drill bits include: rock drilling, geological and mineral exploration, engineering foundation pile construction, water well drilling, support anchoring, open-pit mine step blasting limit holes, complex stratum and pipe drilling, etc. The products of the manufacturing enterprises in the association are mainly concentrated in rock drilling products, and capable enterprises must pay attention to product expansion.
Now that the drilling rig industry is developing rapidly, pay attention to the development trend of integrated machinery and tools in the drilling rig industry.
Compared with large foreign manufacturers of drilling tools, there is currently no one enterprise that can produce a full range of products, let alone supporting the production of machinery and tools. Down-the-hole drilling tool enterprises have relatively strong equipment capabilities and technical strength. It is necessary to understand drilling machinery, construction methods, and accumulate knowledge for product extension.
In terms of down-the-hole drilling tool products, we can develop our own series of products and gradually form our own enterprise product field in the market.
Compared with hydraulic drilling tools, our country’s down-the-hole drilling tools have greater development potential and broader market space. With the increase of manufacturing enterprises, we hope to enter a virtuous circle of development and avoid product price competition at the expense of cost reduction.
VIII. Tricone bits for mining
At present, several domestic enterprises producing mining tricones are mainly concentrated in Jiangsu, Jiangxi, Liaoning, Henan, Hubei, Sichuan and other regions. Among them, Suzhou Xinrui Alloy Tools Co., Ltd. is the largest domestic manufacturer. On the market, tricone bits are mainly products with diameters of 250mm and 310mm. At present, due to the sluggish iron and steel industry and the reduction of surface vein resources in large open-pit iron mines, some open-pit iron mines have begun to reduce production or move to underground mining. In addition, in order to reduce production costs, some mines have begun to choose PDC diamond composite drill bits as drilling tools. Therefore, the domestic use of tricone bits has declined recently. In order to make up for the decline in domestic market demand, some manufacturers have increased their exports to Australia, South America, Eastern Europe and Mongolia to ensure a balanced sales market.
At present, there are only 3-4 domestic drilling tool manufacturers that produce rolling scraper bits for raised drilling tools, and the annual output value is only tens of millions of yuan. The products are mainly exported to the international market, and the utilization rate in domestic large-scale underground mines is not yet popular.
The production of tricone bits requires considerable equipment (forging, machining, heat treatment) and production technology. At present, the company with the best domestic production equipment and product quality is Suzhou Xinrui Alloy Tools Co., Ltd.
In recent years, the number of enterprises involved in the production of roller cone bits has continued to increase. At present, the production of roller cone bits in the association are mainly enterprises in Suzhou, Anshan, Benxi, (Zhuzhou) and other places. The association hopes to strengthen ties with production enterprises in Jiangxi, Luoyang, Hubei, Hebei, Sichuan and other places.
