Passivation Layer Thickness Measurement
Passivation layer thickness measurement determines the thickness and quality of the chromium oxide layer on steel using electrochemical reduction or XPS. It verifies that a corrosion-resistant barrier has been formed.
Physico-Chemical Mechanism of Action
Passivation layer thickness measurement gauges the thickness of the chromium oxide layer on steel. This layer forms through electrochemical reduction or is analyzed by XPS (X-ray Photoelectron Spectroscopy). It shields the metal against corrosion by forming a corrosion-resistant protective barrier.
Metallurgical Relevance & Welding Risks
A too-thin chromium oxide layer can compromise corrosion resistance and lead to premature material failure. A too-thick layer can affect weldability, causing stresses or cracks. Therefore, accurate measurement is crucial for weld quality.
Workshop Practice & Instructions
Use a specialized passivation thickness gauge to measure the chromium oxide layer on the steel. Measure after welding and before applying anti-corrosion treatments. A typical effective passivation thickness ranges from 10 to 20 nm. If measurements are off or passivation is absent, re-welding is required.