Effects of Cryogenic Time on Microstructure and Properties of 2906 Super Duplex Stainless Steel

The effects of cryogenic treatment time (0 h,4 h,8 h,12 h) on the microstructure,mechanical properties and corrosion resisting property of 2906 super duplex stainless steel (SDSS) after solution treatment were studied by means of optical microscope(OM),X-ray diffraction(XRD),environmental scanning electron microscope(ESEM),universal testing machine,rockwell hardness tester and electrochemical polarization curves.The results indicated that the γ phase content and the hardness increased first and then dropped with the extension of the cryogenic time;the corrosion resistance of this material increased with the extension of cryogenic time;cryogenic treatment could reduce the tensile strength,and the longer the cryogenic time,the less the strength values;the main fractography was composed of dimples;elongation reached the maximum after cryogenic treatment for 4 h.