Investigation of the effect of explosive welding variables on the corrosion behavior of the joint of St۵۲ steel – copper sheets

In this research, the effect of explosive welding variables on the behavior and corrosion properties of dissilar joining of copper to St۵۲ steel in NaCl environment was investigated. The explosive welding process was carried out with different combinations of explosive materials that lead to different collision velocities. For this purpose, samples A, B and C were welded with explosives of ۸۰% ANFO + ۲۰% TNT, ۹۰% ANFO + ۱۰% TNT, and ۹۵% ANFO + ۵% TNT, respectively. Examination of the bonding surfaces was carried out with the help of optical and scanning electron microscopes. The results showed that with the increase of the explosive with higher explosive velocity (TNT), the interface changed from a smooth state to a wavy state. Moreover, the microhardness measurement results showed that the hardness of the samples around the interface increased with the increase of the high-explosive substance. Examining the results of electrochemical impedance spectroscopy, it was found that with the corrugation of the joint interface, the value of n (non-uniformity coefficient of the surface) decreased so that the highest corrosion was recorded in the sample with the combination of ۸۰% Anfo + ۲۰% TNT. The results of toefl polarization curves showed that the lowest corrosion rate was related to the sample with the explosive charge combination of ۹۵% ANFO + ۵% TNT and the highest corrosion rate was related to the sample with the explosive charge combination of ۸۰% ANFO + ۲۰% TNT.

کلیدواژه ها:

Explosive welding ، Polarization test ، Explosive charge ، Electrochemical impedance test