Effect of Returns Smelting on Structure and Mechanical Properties of K414 Alloy

The Ni-based superalloy K414 was melted by using of 100% returns,and the returns was recycled 4 times.The chemical composition,mechanical properties and the microstructure of green and reverted alloy were investigated.The results show that with the returns smelting times increasing,the main chemical compositions of the reverted alloy was stable basically,the gas element contents did not distinctly increase,and it was not necessary to add B and Ce elements to the melt during the melting process;there was no substantial difference between reverted alloy and green alloy in morphology;with the return times increasing the tensile properties of reverted alloy at room temperature show a slight downtrend,while their elongation and impact toughness were increased compared to the green alloy;the tensile strength properties increased slightly,reduction of necking area decreased slightly at 600 ℃,while their creep rupture life were reduced compared to the green alloy,and the mechanical properties and creep rupture life time for these reverted alloys are clearly better than the current standard requirements for K414 alloy.The quality of reverted alloy is similar to the green alloy.