Corrosion characteristics of plasma spray, arc spray, high velocity oxygen fuel, and diamond jet coated 30MnB5 boron alloyed steel in 3.5 wt.% NaCl solution

Abstract 30MnB5 boron alloyed steel surface is coated using different coating techniques, namely 60(Ni-15Cr-4.4Si-3.5Fe-3.2B 0.7C)-40(WC 12Co) metallic powder plasma spray, Fe-28Cr-5C-1Mn alloy wire arc WC-10Co-4Cr (thick) high velocity oxy-fuel (HVOF), and (fine) diamond jet HVOF. The microstructure of the crude sample consists ferrite pearlite matrices iron carbide structures. intermediate binders are well bonded to substrate for all surfaces. spray shows formation lamellae. cross-section HVOF surfaces indicates WC, W2C Cr, W parent matrix corrosion characteristic has been investigated in 3.5 wt.% NaCl solution electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), energy dispersive X-ray (EDAX) techniques. results reveal that corroded medium despite coatings. However, extent varies. demonstrated highest resistance while exhibited least. EDAX mapping reveals elements coatings order their standard electrode potential (SEP). Higher linked low SEP tungsten.