Effect of Tannic Acid on the Corrosion Behavior of W18Cr4V in a Simulated Wood Environment and Its Inhibition Mechanism

This study explores the effect of tannic acid on the corrosion of woodworking tool material W18Cr4V in a simulated wood environment. The weight loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy were used to study the corrosion and the corrosion inhibition process of W18Cr4V in an environment of acetic acid solution with different concentrations of tannic acid. The results show that after continuous immersion for 20 h, low concentrations (1 wt% and 3 wt%) of tannic acid promoted the corrosion of W18Cr4V, while high concentrations (5 wt% and above) of tannic acid had a significant anti-corrosion effect, with a corrosion inhibition efficiency of about 64% for 10 wt% tannic acid. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy were used to further verify and elucidate the inhibition mechanism. It was found that tannic acid can form a dense and effective corrosion inhibition film composed of iron–tannin complexes on the surface of W18Cr4V. This study not only provides a new perspective on understanding the corrosion effect of tannic acid on woodworking tools but also offers new insights for developing effective bio-corrosion protection strategies.