Japan is also 70 years to exhaust standard requirements. The automobile manufacturers to increase three-way catalytic device in a vehicle exhaust system to clean exhaust emissions. In the late 1980s, the Japanese government also on the life of an automotive exhaust system makes provision, thereby speeding up the promotion of ferritic stainless steel applications. Currently in Europe, the United States and Japan cars, automobile exhaust system has been 100% stainless steel, especially in recent years, to meet the rising exhaust temperature, the use of high temperature, corrosion-resistant stainless steel instead of aluminum castings and Pipe has been a carmaker’s widely used. Early, Japan, the United States, Europe and other widely used stainless steel automotive exhaust systems, the main material is 304 stainless steel. Automotive exhaust system from the side close to the engine starts, the exhaust manifold, front pipe, flexible pipe, catalytic converter, the middle pipe, muffler and tailpipe and the like. Being dependent on the shape of the car, and some also installed a number of catalytic converters and vice muffler. Automotive exhaust system with stainless steel because of its location is different. The performance requirements of the material vary. In the tube manifold and the opposite end of the high temperature, since the components directly connected to the engine, so the high temperature performance, such as high-temperature fatigue properties, thermal fatigue, high temperature oxidation and other requirements. At the same time, forming a complex manifold because of the material forming process performance is also put forward higher requirements. Automotive exhaust system catalytic converters bear ternary catalyst, their effective catalysis occurs ambient temperature exceeds 1000, so the catalytic converter used for the same material of the housing is required to have good high temperature oxidation. Meanwhile, due to the location of the catalytic converter is easy to contact with the outside world, especially in coastal areas and snowmelt used cars, the catalytic converter housing is also susceptible to the corrosive effects of salt corrosion of high temperature, high temperature salt corrosion properties of the material is very important. For pipe-in-pipe and muffler before connecting, the use of temperature at about 600, the main failure is high temperature salt damage. Muffler exhaust system is an important part of its material failure is mainly condensate corrosion failure. Stainless steel welded pipe production which we can select the appropriate pipe processing method according to the type of pipe material, pipe wall thickness and conditions of use. Automotive Exhaust System pipe for pipe expansion when the elbow and higher processing requirements, in addition to the pipe material itself has higher requirements, and further improve the quality of the welded seam is also very important. Automotive Exhaust System ferritic stainless steel welded pipe production, from weld quality to consider. Laser welding is the best method, high-frequency welding of the highest productivity. Application of laser welding technology, can ferrite grain growth HAZ harm reduced to a minimum, ensure that there is sufficient heat affected zone toughness, cold deformation meets the requirements of the exhaust pipe.
------------
ABOUT THE AUTHOR
stainless steel welded pipe and stainless steel seamless pipe from Hunan great steel pipe