The problem of blowing white powder from the air conditioning box of the test car is analyzed by means of energy spectrum and metallographic analysis, and it is confirmed that white powder is an oxide of aluminum formed after corrosion of the evaporator. Through infrared and corrosion resistance test analysis, the results show that the serious corrosion is caused by the evaporator in a humid environment in which galvanic corrosion occurred under the catalysis of Cu. The solutions such as replacing materials and using passivation and hydrophilic chemicals with higher corrosion resistance are proposed so as to effectively solve the problem of blowing white powder in air conditioning boxes because of the evaporator’s corrosion.

Air conditioning box  /  Evaporator  /  White powder  /  Corrosion