Corrosion inhibition of imidazoline and porphyrin on hot-pressed impregnated diamond bits in NaCl solution

The corrosion inhibition behavior of imidazoline and porphyrin in hot pressing impregnated diamond bit matrix material in NaCl solution with pH10 and mass fraction of 20% was studied by electrochemical method, weight loss test and Raman spectroscopy. The results show that both imidazoline and porphyrin can promote the formation of passivation films (mainly copper and iron oxides) on the surface of matrix materials, which can play a role of corrosion inhibition. Due to the hydrolysis of imidazoline under alkaline conditions, the inhibition efficiency of imidazoline in the electrochemical test is significantly less than that of porphyrin. The one-week weightlessness test shows that prolonged soaking can increase the inhibitory efficiency of imidazoline to the same level as porphyrin.