作　　者： ; ; ; ; ; ; ;

机构地区： 中南大学材料科学与工程学院

出　　处： 《材料科学与工艺》 2009年第3期301-304,共4页

摘　　要： 为改善2519A-T87铝合金的腐蚀性能并探求其影响因素,采用金相显微镜、透射电镜及X射线衍射仪研究了锻造以及轧制两种变形方式对该合金板晶界无沉淀带、析出相、晶粒取向与抗腐蚀性能的影响.结果表明:锻造板中晶界无沉淀带(PFZ)较轧制板的宽,晶界析出相粒子间距大,较难形成连续腐蚀通道,其抗晶间腐蚀与剥落腐蚀性能优于轧制板;PFZ与基体,析出相与PFZ构成两对电偶发生反应,而晶界上不连续分布的、大的第二相之间的间距有利于提高合金的抗应力腐蚀性能,锻造板的应力腐蚀性能(KISCC=32.1 MPa.m1/2)比轧制板(KISCC=22.1 MPa.m1/2)高;锻造板的{100}晶粒取向密度较低;第二相的大小及分布是决定该合金腐蚀性能的关键.. To improve corrosion properties of aluminum alloy 2519A plate, the effects of forging and rolling deformation on microstructures and corrosion resistance were investigated by optical microscopy （OM） , transmission electron microscopy （TEM） and orientation distribution function （ODF）. Results show that compared with the precipitate free zones （PFZ） in the rolled plate, those in the forged plate are wider and the distance between the precipitates along grain boundaries （GBs） is larger. Upon etchant immersion a continuous corrosion path is hard to form in the forged plate, which leads to higher resistance of intergranular corrosion and exfoliation corrosion. Two galvanic cells coexist between PFZ-matrix and precipitates along GBs-PFZ, of which the precipitates with large distance along GBs determine SCC resistance, i.e. forged plate has better stress corrosion cracking properties （ K iscc = 32. 1 MPa · m^1/2 ） than rolled plate （ K iscc = 22. 1 MPa · m^1/2 ）. The o- rientation density of { 100 } texture is much lower in forged plate. The size and distribution of the second phase play a key role in the corrosion resistance of aluminum alloy 2519A plate.

关 键 词： 锻造 轧制 晶间腐蚀 剥落腐蚀 应力府蚀 织构

领　　域： [金属学及工艺] [金属学及工艺]