The fracture mechanism of aluminum plate-fin structures in liquefied natural gas field at room/low temperature
To avoid strength damage and improve the service life of LNG aluminum plate-fin heat ex-changers,the tensile fracture mechanism of their aluminum plate-fin structures at room/low temperature is studied using axial tensile testing and scanning electron microscope observation.The result shows that,compared to mechanical properties at room temperature,the yield limit of plate-fin specimens at low tem-perature increases by 42.6％,the tensile strength increases by 48.9％,and the strain increases by 27.8％during failure.The fracture trend of plate-fin specimens at room/low temperature conditions primarily in-volved crack propagation from the fin root and vice versa.The overall fracture morphology of cleavage sec-tions and dimples account for a large area of fracture surface.However,the morphology of cleavage sec-tions is observed with high distribution at low temperature,and the plastic morphology accounts for a small area of fracture surface.The fracture of plate-fin specimen at room temperature is mainly located in the brazing zone,whereas the fracture at low temperature is confined to the brazing zone.Therefore,the fracture of the aluminum plate-fin structure in the brazing zone can be avoided by improving the brazing process of the aluminum plate-fin structure and increasing the solder in the brazing zone.
万方数据
维普
