| Popis: |
High strength steel has been developed to meet the needs of weight reduction in automotive industry. To get high strength (tensile strength over tan 780 mega pascal), phase transformation and complex phases (ferrite, martensite) has been employed in steel alloy design with addition harden ability element such as silicon and manganese. The electrochemical and corrosion behavior of high strength steel is different from the general mild steel. Complex phase steel shows a good general corrosion resistance property but a poor perforation corrosion. The interfaces of phases(Ferrite-Martensite) plays a role of corrosion initiation site. The corrosion product of complex phases steel(high strength steel) accelerates perforation corrosion comparing general mild steel(single phase). The corrosion rate depending on the phase fraction (full ferrite, 20% Farrite, 50% Ferrite 80% Ferrite and full Martensite) was monitored under corrosion acceleration test for 40 days. The corrosion mechanism of complex phase steel will be discussed in this study. |
