【摘要】 运用JMatpro7.0模拟软件,通过末端淬火(Jominy end-quench)试验,结合透射电子显微镜(TEM),研究了6005A合金的淬火特性及微观组织特征.结果表明:JMatpro7.0模拟软件揭示6005A合金的淬火敏感区间为280～400℃,临界冷却速率应大于5℃/s;合金时效态的硬度随着距淬火末端距离D的增加而降低,6005A合金的淬透深度为35 mm;末端淬火过程中,淬火析出相β相优先在晶界析出,其次在弥散体α-(AlMnFeCrSi)相上析出.慢速淬火过程中,时效态硬度下降的原因如下:(1)时效过程中,晶内强化析出相β″相减少,棒状β′相的面积分数增加;(2)慢速淬火过程中,不均匀弥散体α-(AlMnFeCrSi)相上析出片状β相,在后续时效过程中β相长大,吸收周围的溶质原子,使得合金的过饱和固溶体的程度下降;(3)慢速淬火下,晶界附近的空位浓度减少,晶界无沉淀析出带(PFZ)宽化.更多还原

【Abstract】 Quenching characteristics and microstructure characteristics of 6005 A alloy were studied by JMatpro7.0 simulation software and through the end-quenching(Jominy end-quench) experiment combined with transmission electron microscope(TEM). The results showed that JMatpro7.0 simulation software revealed that the high quenching sensitivity temperature zone of 6005 A alloy is 280℃-400℃, and the critical cooling rate should be greater than 5℃/s. The aging hardness of the alloy decreases with the increasing of the distance D from the quenched end, and the aging hardening depth of 6005 A alloy is 35 mm. During the end-quenching process, the quenched precipitate phase β primarily precipitated on grain boundary, and then on α-(AlMnFeCrSi) dispersiod. During the slow quenching process, the reasons for the decrease of hardness in aging state are as follows:(1) During the aging process, the intragranular strengthening precipitate β ″ decreases, and the area fraction of the rod-like β ′ phase increases.(2) During the slow quenching process, the lamellar precipitated phase β precipitates on the α-(AlMnFeCrSi) phase. During the subsequent aging process, the β phase grows and absorbs the surrounding solute atoms, which reduces the degree of supersaturated solid solution of the alloy.(3) Under slow quenching, the vacancy concentration near grain boundary decreases, and the precipitate free zone(PFZ) widens.更多还原