Marine High-magnesium Alloy Corrosion Yield Behavior And High Temperature Deformation Behavior Study

In this paper,the corrosion resistance,yielding behavior and the behavior during hot compression deformation of high Mg 5XXX aluminum alloy with different Mg content and different treatment have been studied by means of the slow strain-rate test,isothermal compression simulation test,DSC analysis,micro-hardness testing,electro-chemistry characteristic,metallographic microscope,SEM, TEM.Experimental results show:1.The low SCC resistance and intergranular corrosion resistance of the as-quenched alloy annealing at 150℃for 1 huor is relate to more and largerβphase precipitate after 150℃1 hour aging than the same Mg content alloy as-quenched or after 350℃1 hour aging.The same treatment alloy with lower Mg content has better corrosion resistance than the one with higher Mg content under the same condition.The serrated yielding intense of alloy after 150℃aging reduce when adding aging time.Low serrated yielding intense,elongation and high UTS is relate to more and largerβphase precipitate after 150℃1 hour aging than the same Mg content alloy as-quenched or after 350℃1 hour aging.2.The as cold-rolled alloy has the worst exfoliation corrosion resistance due to exist of residual stress.The precipitated temperature ofβphase reduce when increase reduction of cold-rolled treatment,which induce the different effect of heat treatment temperature to corrosion resistance of alloy.After recrystallization is completed,the smaller the recrystallized grain the longer the Luders elongation.The frequency of serrations also increases with decreasing grain size.The frequency of serrations decreases and the magnitude of serrations first increases and then decrease with increase in strain.The cold-rolled sample which has higher dislocation density has more intense serration than the sample after recovery heat treatment.3.To the 5A01 alloy after homogenization annealing:The stress increase with the strain rate at the same compression temperature,which show 5A01 aluminum alloy is positive strain rate sensitivity material,the stress increase with the compression temperature at the same strain rate. Deforming degree has little effect on the stress at the strain rate and the same compression temperature.The flow stress of 5A01 aluminum alloy during hot deformation can be expressed by Arrhenius function in the hyperbolic sine style.The values of A,α,n and Q in the analytical expression are 0.06831s^-1,0.0094MPa,2.7089 and 161.14KJ/mol.