Study on derived hydrogen and ignition influencing factors of moist magnesium debris

•Moist Mg debris erosion reaction rate rises and then falls as moisture content rises.•High temperature adds ignition potential of moist Mg debris erosion reaction system.•The raising specific surface area of moist Mg debris fastens erosion reaction rate.•The raising Mg debris pile layer rises micro-reaction efficiency and water depletion.•Study results offer a reference for the hazard rating sort of active metal storage.