Application of Seamless Steel Tube in Automobile Manufacturing Industry

Seamless steel pipes have a hollow section and are used in large quantities as pipelines for conveying fluids, such as pipelines for conveying oil, natural gas, gas, water and certain solid materials. Automobile welded steel pipe is one of the most important varieties of precision welded pipes. The main varieties are automobile transmission shaft pipes, automobile muffler pipes, automobile condenser pipes, automobile exhaust pipes, automobile control shaft pipes, automobile thrust pipes, Automobile shock absorber oil storage pipe, etc. Seamless steel pipe for automobile axle bushing GB3088-82 is a high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel used in the manufacture of automobile axle bushings and axle tubes of drive axle housings.

In fact, seamless steel pipes are widely used in automobiles. Stainless seamless steel pipes are mainly used in automobile exhaust systems, accounting for more than 1/2 of the total amount of automobile stainless steel, and 80% is ferritic stainless steel. The exhaust gas produced by the car engine flows out of the muffler through the exhaust gas intake pipe, front pipe, hose, converter, and center pipe. Commonly used steel grades for exhaust systems are 409L, 436L, etc. Automobile mufflers mainly use stainless steel welded pipes. According to estimates, stainless seamless steel pipes used in automobiles account for about 1.5% of the entire downstream users' consumption of stainless seamless steel pipes, and the ratio of stainless steel seamless pipes to welded pipes is about 2:1.

In summary, the cantilever frame tube is used for the rear axle of the chassis, and the seamless steel pipe used for the front axle assembly of the chassis includes a shaft sleeve, a bearing sleeve, and a brake foot support tube. Cooling and air-conditioning system pipes mainly include cooling water pipes, air-conditioning pipes, and sensor pipes. Special requirements for steering shock absorber seamless steel pipes include seamless steel pipes for cylinder blocks and seamless steel pipes for liquid storage cylinders. The hollow shaft tube is used for the transmission system. The seat tube is mainly used for the seat frame. Ultra-high-strength seamless steel tubes are used for side door anti-collision bars. It can be seen that seamless steel pipes are widely used in automobiles.

High-strength fasteners for automobiles also use seamless stainless steel seamless steel tubes. According to industry insiders, automobiles are equipment-type products, and fasteners are one of the key components of automobiles. The average amount of fasteners for passenger cars (complete vehicles) is about 37 kg. The domestic supply of high-strength fasteners for cars in my country is less than 25%, and most of them are purchased from abroad. At present, domestic companies such as Baosteel are optimistic about this market and are committed to developing seamless stainless steel pipes.

In the next period of time, hybrid power system will be developed rapidly as a transitional solution. Therefore, new energy vehicles also need seamless steel pipes. Even pure electric vehicles still need seamless steel pipes, such as seamless steel pipes for electric vehicles. damping. Some automobile manufacturers have developed a practical new type of seamless steel tube frame for electric four-wheeled vehicles. The chassis, sub-frame, double longitudinal beams, front upper bracket and rear upper bracket are fixed by seamless steel tubes. Connection forms a whole. Many domestic seamless steel pipe manufacturers have developed shock-absorbing seamless steel pipes for electric vehicles, cold-rolled seamless steel pipes for electric vehicles, etc. This kind of cold-rolled seamless steel pipes for electric vehicles have higher requirements for mechanical properties, so the chemical composition of raw materials, Extensibility requirements are high. At present, the specifications of seamless steel tubes for shock absorption for electric vehicles and cold-rolled seamless steel tubes for electric vehicles are mainly concentrated in the small diameter range.

The "Energy-saving and New Energy Vehicle Industry Development Plan (2012-2020)" proposes that by 2015, the cumulative production and sales of pure electric vehicles and plug-in hybrid vehicles will be close to 450,000; by 2020, pure electric vehicles and plug-in The production capacity of hybrid electric vehicles is expected to reach 2 million, with cumulative production and sales exceeding 5 million. With the implementation of the "Energy-saving and New Energy Automobile Industry Development Plan (2012-2020)", the demand for seamless steel pipes in the automobile industry will be further released. At the same time, the automotive industry has put forward higher requirements for the quality and performance of seamless steel pipes.

Among imported automobile vehicles or parts, about two-thirds of automobile seamless steel pipes are high-precision welded seamless steel pipes and high-precision welded cold drawn (or cold rolled) seamless steel pipes. The lag in the development of such seamless steel pipe products in my country is still dependent on imports to make up. At present, there are few types of welded seamless steel pipes in my country, few applicable specifications, and unstable deburring process of welded seamless steel pipes. Therefore, the development of seamless steel pipes for automobiles generally replaces high-precision welded seamless steel pipes with cold drawn and cold-rolled seamless steel pipes.. In order to save energy and reduce the weight of the car body, the welded seamless steel pipe for automobiles should develop in the direction of high strength and high toughness, so that the welded seamless steel pipe for automobiles in my country can reach or exceed the world's advanced level.

The implementation of the "Energy-saving and New Energy Automobile Industry Development Plan (2012-2020)" will promote the rapid development of my country's automobile industry, and provide market opportunities for the localization of precision seamless steel pipes for automobiles. In addition, new models continue to appear As the requirements for energy conservation and environmental protection in automobiles continue to increase, it is foreseeable that the seamless steel pipe market for automobiles will be huge. According to the empirical data of steel used in various parts of automobile manufacturing, it is estimated that the average steel used for a passenger car is about 1 ton. The steel used for commercial vehicles is in the order of heavy, medium, light, and micro. Tons, 1.5 tons and 0.8 tons, of which special steel accounts for an average of 30%. It can be seen that seamless steel pipes will be very useful in the automotive industry in the future, and the market prospects for seamless steel pipes for automobiles are promising.

Steel pipe industry practitioners at Permanent Steel Manufacturing Co.,Ltd, knowledge enthusiasts