Fe-18Mn-5Si-8Cr-5Ni-0.1N形状记忆合金组织和性能的研究

Study of Microstructure and Properties of the Fe-18Mn-5Si-8Cr-5Ni-0.1N Shape Memory Alloy

研究了Fe-18Mn-5Si-8Cr-5Ni-0．1N形状记忆合金的形状记忆效应、回复应力、耐蚀性能。结果表明，在Fe-18Mn-5Si-8Cr-5Ni-0．1N合金中加入0．1％的氮，对合金的形状记忆效应不利，但当预变形量小于4．5％时，降低幅度较小，在14％～18％左右。在变形量小于4．5％时，含氮合金加热时的回复应力高于未加氮的合金的回复应力；当变形量大于4．5％时，含氮合佥的回复应力低于未加氮的合金的回复应力，两种合金的加热时最大回复应力的最大值相近（90MPa左右）。又由于氮具有强烈的固溶强化作用，大大强化了基体，使得合金在冷却过程中因回复应力导致的塑性变形量和二次相变量减小，从而导致合金冷却到室温的回复应力显著提高，当预变形量为6％时，含氮合金的室温回复应力最大，比未加氮的合金的最大室温回复应力高约21％。同时，氮的加入有利于提高合金的耐蚀性能。

Shape memory effect and recovery stress and corrosion resistance are studied of Fe-18Mn-5Si-8Cr-5Ni-0.1N shape memory alloy. The results show that addition of 0.1wt% nitrogen in solid solution to the alloy suppresses the SMA, but depressed range is on the small side when prestrain less compared with the than 4. 5%, about 14%～18%; recovery stress of the alloy containing nitrogen is higher than that of not containing nitrogen when prestrain less than 4. 5%; recovery stress of the alloy containing nitrogen is less compared with the alloy not containing nitrogen when pre-strain bigger than 4.5%, the greatest recovery stress of two alloys when heated are similar （about 90 MPa）. Because nitrogen possesses effect of strong solid solution intensification, greatly intensifies matrix, therefore making plastic deformation and secondary phase transition due to recovery stress of alloy in course of coolling reduce, accordingly it brings on distinct improvement of recovery stress of alloy at room temperature, recovery stress is highest at room temperature when pre-strain is 4. 5%, 21% higher than the alloy of not contain nitrogen. At one time, the addition of nitrogen improves corrosion resistance of alloy.