Ni-30Cr-1Cu合金晶粒尺寸及晶界沉淀与脆性的关系  

Relation Between Grain Size, Precipitates at Grain Boundaries and Fragility in Ni-30Cr-1Cu Alloy

作　　者：陈国胜[1] 曹美华[1] 周奠华[1] 索进平[2] 

机构地区：[1]上海宝钢集团公司五钢公司,上海200940 [2]华中科技大学,湖北武汉430074

出　　处：《宝钢技术》2003年第6期31-34,共4页Baosteel Technology

摘　　要：用晶界萃取复型技术研究了晶界一次相极少、二次相析出倾向很大的Ni - 30Cr -1Cu合金的晶界沉淀规律。采用不同温度固溶后盐水快速冷却以抑制晶界二次相的析出获得了晶界沉淀状态相近的不同尺寸晶粒 ,结果表明 ,随单纯晶粒长大 ,合金的室温冲击韧性、拉伸塑性均有不同程度的升高。于 1 1 80℃固溶后以不同速度冷却 ,结果显示了随冷却速度减慢 ,晶界M2 3C6 显著增多、分布密度增大 ;其沉淀特征分别由空冷的精细薄片状向缓冷的颗粒状、棒状、薄膜状乃至枝晶状转变 ,使晶界在室温脆化 ,冲击韧性和拉伸塑性显著下降 ;Precipitate varies at the grain boundaries of Ni-30Cr-1Cu alloy.It precipitates little at the primary carbides but much easier at the second carbides.Different grain size with similar amount of precipitates at grain boundaries was obtained after the alloys were in solution at different temperatures and cooled quickly in salt water.Results show that the impact toughness and tensile ductility at room temperature are increased variably together with the increase of the grain size.After being solved at 1180℃ and cooled at different rates,the amount and distribution density of M 23 C 6 at grain boundaries increased remarkably when the cool rate went down.Morphology of precipitates transformed from fine lamellae in air cool condition to particles,rods and films,even to dendrite in slow cool condition.Due to this conformation,grain boundaries became fragile,and the impact toughness and the tensile ductility decreased obviously.Fracture morphology transformed from mixed ones dominated by trans-grain to intergrain fragile ones.

关 键 词：镍基高温合金 晶界沉淀 晶粒尺寸 韧性 塑性 

分 类 号：TG115.5[金属学及工艺—物理冶金]