Hastelloy Pickling and Passivation Process

Pickling and passivating Hastelloy is basically like with stainless steels: you want to etch away the heat tint and scale from welding because they kill corrosion resistance. For that, use a suitable acid mixture – usually based on nitric and hydrofluoric acid – apply it or bath the part in it until the surface is clean and evenly metallic shiny again. Then rinse thoroughly with water, otherwise the acid will eat holes in the weld later.