Research On Seawater Corrosion Resistance Of Low Carbon Steel Containing Titanium

Steel is widely used in the marine environment, because of its low price, high strength and toughness. The corrosion resistance of steel used in marine environment is an important indicator of steel, but the study of seawater corrosion is far behind the study of atmospheric corrosion. At present, seawater corrosion mechanism is still unclear. The titanium has good corrosion resistance, but the impact of the titanium in the carbon steel on seawater corrosion has not been well studied. This paper has studied the impact of Ti on seawater corrosion by changing the massfraction of Ti in carbon steel.In this study, three-furnace steel is smelted to compare with industrial steel. homogeneous immersion, polarization curves and impedance spectroscopy detection experiments have been done to investigate the seawater corrosion resistance of steels; Using electron probe to observe rust section and rust layer element accumulation; Using XRD to analyze rust corrosion products of phase composition of Ti elements on the effects of corrosion resistance and corrosion mechanism of carbon steel. The conclusions were as follows by experiment.(1) Uniform immersion experiments show that:the relationship of corrosion resistance in several experimental steels is1#>2#>3#>EH36.(2) Conducted via XRD phase analysis indicates that:the corrosion products of the several experimental steels are α-FeOOH, FeOOH, γ-FeOOH, Fe3O4, Fe2O3,1#steel contents more α-FeOOH than other experimental steels. EH36contents the least α-FeOOH.(3) Electrochemical experiments show that:the corrosion voltage relationship of the experimental steels with crossing in15days,30days,45days,60days is1#>2#>3#>EH36; With the prolonged carbon steel corrosion, the voltage of ecorr rises; From fitting the AC impedance knows:with the corrosion time increasing, rust resistance increases, the resistance of the electric charge passes rust layer increases.(4) Electron microprobe experiments show that:Si, Ni, Ti in the rust layer are different levels of enrichment; the enrichment of Si in outer rust layer is greater than the concentration of Si inside the rust layer;1#,2#,3#all have TiN inclusions. (5) The corrosion potential of carbon steel is significantly improved as the pH rises.(6) Carbon steel in NaCl concentration from0%to2%, mass loss increases, and in NaCl concentration from2%to3%, mass loss reduces.