Surface Activity of HR-2 Stainless Steel in Acid Solution with SECM

By surface scanning technology and linear scanning technology with SECM,which have a micrometer pixel,corrosion behavior of HR-2 stainless steel in 0.5 mol/L H_2SO_4+0.1 mol/L NaCl solution was studied.The results show that:open circuit potential,activation potential,and passivation potential are -0.4 V,-0.23 V,0.0 V ~ 0.8 V relatively.The maximum current of probe is 9.5 nA when substrate current is open circuit potential 35.2nA,when substrate current is activation potential.When passive film formed on the substrate,the current of probe largely decreased.H_2 was obtained when current of probe is -0.2 V,Fe~(2+) was obtained when current of probe is 0.6 V.It is also observed that the proper distance between probe and substrate is 20μm, and best concentration of the corrosion inhibition(sulfocarbamide) is 0.75 mmol/L.