A Study on the Rust Removal and Retard on the Surface of the Wear Water Screw-Thread Steel Using Flame Hot Melting

Abstract

Screw-thread steel, which is produced using the quenching process through wear water controlled rolling system, would prone to generate red rust on its surface. For this reason a combustion apparatus with a smoke backflow area containing partly unburnt combustible fuel is designed to study the rusted 20MnSi wear water screw-thread steel under high temperature flame hot melting. With SEM/EDS and XRD analysis we could affirm that the main composition of the red rust is Fe2O3It assumes loose, porous branches and leaves, therefore makes the absorption of water and gas easier and intensified the sprawling of corrosion. While the steel surface after hot melting treatment form a tight passivation layer made of Fe3O4and FeO, which would isolate outer circumstance thereby protects the metal body. In the article we analyzed two main reasons that cause the red rust and point out contents that requires further studies. Compared with using chemical addition agent, this high temperature flame hot melting reaction technique is beneficial to the environment while of lower cost.