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5974 |
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Tuesday, May 21, 2019, Saal Brüssel 5:00 PM Properties of brazed joints 1 |
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Investigation on corrosion behaviour of 316L stainless steel brazed joints with a new amorphous nickel-based filler metal
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Hong Li* / Beijing University of Technology, P.R. China Yueyue Li / Beijing University of Technology/College of Materials Science & Engineering, China Jacek Senkara/ Warsaw University of Technology/Welding Engineering Department, Poland Zhuoxin Li/ Beijing University of Technology/College of Materials Science & Engineering, China Hongshou Zhuang/ Beijing University of Aeronautics and Astronautics/School of Mechanical Engineering&Automation, China |
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Exhaust gas recirculation (EGR) is commonly used to reduce NOx emissions from automotive diesel engines. However, the materials and brazed joints for EGR system have to resist the erosive environment as well as static and cyclic loads. In the present study, the behavior of stress corrosion cracking of AISI 316L stainless steel joints brazed by using a new amorsphous BNi685 filler metal is investigated at first. The influence of the condensate K1.2 corrosion according to VDA 230214 on the tensile strength and stress corrosion cracking of the brazed joints under the constant load is studied. The residual strength of the joint was measured after 120h to evaluate the stress corrosion resistance. SEM images show that the failure location is within the brazed zone. In addition, the corrosion fatigue behavior of brazed AISI 316L/BNi685 joints were cyclically tested in the condensate K1.2 under stress control until a maximum of 2×106cycles. As the stress level is decreased, the influence of stress and corrosive medium on the fatigue behavior of brazed AISI 316L/BNi685 joints weaked gradually. While with the further decrease of stress level, the joints will not undergo stress corrosion. The results show corrosion fatigue cracking of brazed joints is also located in the brazed zone. A significant reduction of the fatigue strength at 2×106 cycles is down to 43%. The fracture morphology analysis indicates that the brazed joints exhibit the brittle fracture characteristics. |