Electrochemical characteristics of white layer generated by hard milling AISI H13 steel

Abstract

In the field of hard cutting, researches on white layer have become more extensive and in-depth in recent years, because white layer has an important influence on the performances and life of components. Nevertheless, properties of white layer, especially its corrosion properties, have not been well understood or clearly defined. In this study, specimens with different subsurface microstructures (no obvious change, dark layer, and white layer) were produced in the process of tool wear to analyze their electrochemical properties using electrochemical methods. It was found that electrochemical properties were distinct between specimens with and without white layer. A specimen with white layer had obviously lower electrochemical impedance and more anodic steady-state open-circuit potential than that without white layer in 3.5 wt.% NaCl solution. That is to say, specimens with white layer were prone to corrosion in this solution. The results also manifest that electrochemical method can be a reliable, convenient, and nearly nondestructive method to detect white layer.

The Effect of Technological Conditions of Hard Turning on the Formation of White Layer

“…The findings of Yan et al [17] are interesting and important from the point of view of practical technology. They proved that the formation (presence) of a white layer can be demonstrated by a nondestructive electro-chemical method, in 3.5 wt% NaCl solution, since in this solution the specimens with a white layer were susceptible to corrosion in a way different to those with no white layer.…”