Abstract: This paper introduces the development and application of high-strength materials at home and abroad, analyzes the feasibility and welding process of high-strength materials on trackless rubber tire vehicles, and points out the advantages of CO2 arc welding of flux cored wire. With the high-yield and high-efficiency development of coal mine production, underground auxiliary transportation machinery is also developing in the direction of lightness and reliable operation. The trackless rubber tire vehicle is a new type of high-efficiency underground auxiliary transportation machinery, which has the characteristics of high transportation efficiency, fast and flexible, time and labor saving, high safety and low operating cost, and has broad application prospects. In the United Kingdom, the United States, Australia and other countries, trackless rubber tires have a history of more than 20 years, and have been used in large numbers, and achieved remarkable results. There is currently no stereotyped product in China. To this end, on the basis of digesting Australia's Truk4 and Pet6 passenger and cargo vehicles, combined with domestic use, the development of FKH6 underground explosion-proof and low-pollution medium-sized passenger and cargo dual-purpose rubber tire vehicles was carried out to accelerate the realization of China's coal mine auxiliary transportation modernization. Reduce the gap with the world's advanced level. 1 Introduction of high strength steel plate In recent years, with the development of large-scale equipment, countries around the world are strengthening the development of high-strength steel sheets, developing low-alloy steels with good processing performance, excellent performance and low cost, such as boron steel, manganese steel, high-silicon steel, etc. Advanced metallurgical technology, steel rolling process and heat treatment process to improve the metallurgical quality, strength and toughness of steel. For high-strength steel sheets, welding is often required for both structural and wear parts. Therefore, improving the strength of materials and improving the toughness and weldability of materials has become a worldwide trend in the development of low-alloy high-strength steels, and its application range is also increasingly widespread. Such materials have been widely used in construction machinery, mining equipment, etc., for example. The following focuses on the mechanical and welding properties of representative EEMS10072 steel sheets. 1.1 Chemical composition and mechanical properties of EEMS10072 steel plate Table 1 EEMS10072 steel chemical composition% Table 2 Mechanical properties of EEMS10072 steel Brake Heavy Duty Casters,Side Brake Castor,High Temperature Wheel Castor Middle Duty Caster Co., Ltd. , http://www.nbcasters.com
Keywords: trackless Rubber Wheel material welding process flux cored wire
FKH6 underground explosion-proof and low-pollution medium-sized passenger and cargo dual-purpose rubber tire vehicles are mainly composed of explosion-proof engine devices, explosion-proof systems for intake and exhaust and electrical appliances, hydraulic transmission devices, driving controls, articulated frames, passenger and cargo vehicles, hydraulic and pneumatic systems. And other components. Among them, the frame is an important bearing structure of the car, and the two parts of the front and rear frames are both made of high-strength steel plate welded structure. The front and rear frames are hinged by a hinged turntable. The frame is mainly used for installing power, transmission, walking control and other components and load-bearing materials, and the stress condition is relatively complicated. Therefore, the structural performance of the vehicle has a direct relationship between the performance and life of the vehicle. In order to ensure the overall performance and transportation efficiency of the rubber tire vehicle, the frame is required to have its own strength, rigidity and reliable load capacity, and reduce its own weight as much as possible to increase its load capacity, reduce costs and obtain higher Economic benefits. To this end, we selected the British Terex EEMS series 1008, 10083 and 10072 high-strength steel plates as the material for the trackless rubber wheel frame, and explored the technical approach used.
EEMS10072 steel is a quenched and tempered low carbon manganese boron steel from Terex Corporation of the United Kingdom. The best comprehensive performance can be obtained by controlling the rolling temperature. Hot-rolled, quenched (water quenched) and tempered above 430 ° C, with high strength and plasticity, especially with high low temperature toughness, and good ductility and formability, it has been widely It is applied to large-scale self-unloading mining trucks for construction machinery, which has the characteristics of high reliability and long fatigue life. The chemical composition and mechanical properties of the steel are shown in Tables 1 and 2, respectively. Plate thickness δ/mm ω(C) ω(Mn) ω(Si) ω(S) ω(P) ω(Ni) ω(Cr) ω(Mo) ω(B) 4.8 ≤ δ <15.9 ≤0.2 ≤1.35 0.15～0.4 ≤0.05 ≤0.04 - - - ≤0.0005 15.9 ≤ δ < 25.4 ≤0.2 ≤1.6 0.15～0.4 ≤0.05 ≤0.04 - - - ≤0.0005 25.4 ≤ δ < 50.8 ≤0.24 ≤1.6 0.15～0.4 ≤0.05 ≤0.04 ≤0.25 ≤0.25 ≤0.08 ≤0.0005 σ b /MPa σ s
/MPa δ
/% A kv (-45°C)
/J HB ≥690 ≥621 ≥16 ≥20.3 229~285
The carbon equivalent of different thickness EEMS10072 steel plates can be calculated according to the carbon equivalent calculation formula recommended by the International Welding Society (see Table 3): 
Table 3 EEMS10072 steel plate carbon equivalent C eq Plate thickness δ/mm ω(C eq )/% 4.8 ≤ δ <15.9 0.42 15.9 ≤ δ < 25.4 0.46 25.4 ≤ δ < 50.8 0.50
The higher the carbon equivalent ω (Ceq) value, the greater the tendency of the steel to harden and the greater the cold crack sensitivity. When ω(Ceq)>0.45% to 0.55%, the welding is prone to cold cracking. It can be seen from Table 3 that when the sheet is thin (δ<12 mm), the weldability is good; and for the sheet with δ ≥ 12 mm, pre-weld preheating and post-weld technical treatment should be performed to avoid cracks.
Application of high-strength materials on trackless rubber tire vehicles
1.2 Analysis of welding performance of EEMS10072 steel
The content of each element in the formula is shown in Table 1.
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