CAJ | 학술논문

研究了浇注后不同的冷却速率对MX246A合金组织和持久性能的影响.结果表明,组织特征只受该组织形成时的冷速影响.冷速从30℃/min降到8℃/min时,晶粒增大,共晶γ'的体积分数从1.86%减少到O.86%,尺寸从30μm增大至50 μm;冷速从30℃/min降到4℃/min时,枝晶干γ'尺寸由0.93μm增大至3.09μm,边界由平直转为圆滑,碳化物颗粒变大,数量减少;枝晶干γ'和碳化物的尺寸和形貌对高温持久性能影响较大.当冷速为30℃/min时,获得较小尺寸、边界平直的枝晶干γ'和细小弥散分布的碳化物,持久性能较好.
연구료요주후불동적냉각속솔대MX246A합금조직화지구성능적영향.결과표명,조직특정지수해조직형성시적랭속영향.랭속종30℃/min강도8℃/min시,정립증대,공정γ'적체적분수종1.86%감소도O.86%,척촌종30μm증대지50 μm;랭속종30℃/min강도4℃/min시,지정간γ'척촌유0.93μm증대지3.09μm,변계유평직전위원활,탄화물과립변대,수량감소;지정간γ'화탄화물적척촌화형모대고온지구성능영향교대.당랭속위30℃/min시,획득교소척촌、변계평직적지정간γ'화세소미산분포적탄화물,지구성능교호.
Effects of different cooling rates after pouring on microstructures and stress rupture properties of MX246A alloy have been studied.The results show that microstructures of MX246A alloy are influenced only by the cooling rate at the certain time when the microstructures are formed.With the reduction of cooling rate from 30 ℃/min to 8℃/min,size of grains becomes lager,volume percent of primary γ'decreases from 1.86%to O.86%and size of primary γ'increases from 30 μm to 50 μm;when cooling rate reduces from 30℃/min to 4℃/min,size of dendrite stem γ'changes from 0.93 μm tO 3.09 μm with its morphology from rectangular to cellular.It is concluded that size and morphology of dendrite stem γ'and carbides are the most important contributions to high temperature stress rupture property:when the cooling rate is 30℃/min,stress rupture propeny of MX246A is better,which may be attributed to the small and.rectangular dendrite stem γ'and fine and dispersed carbides.