(1．北京工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，北京 100124；
2．東風(fēng)商用車技術(shù)中心 工藝研究所，武漢 430056)
摘 要: 采用晶間腐蝕性能測試及透射電鏡研究冷變形及退火對5E06鋁板晶間腐蝕性能的影響規(guī)律。結(jié)果發(fā)現(xiàn)：5E06鋁板的晶間腐蝕性能與β相的分布、形貌和析出量密切相關(guān)。當(dāng)冷變形量低于40%時，β相較易在晶界析出達(dá)到連續(xù)而使合金晶間腐蝕性能惡化；當(dāng)變形量增加到55%以上時，經(jīng)穩(wěn)定化退火后β相在晶界不容易連續(xù)，5E06鋁板晶間腐蝕性能良好。進(jìn)一步的敏化試驗表明，經(jīng)55%~80%冷變形的5E06鋁板在120 ℃穩(wěn)定化退火的效果并不理想，而220℃的穩(wěn)定化退火由于獲得了比較均勻的亞晶組織且β相在晶界/亞晶界斷續(xù)分布并一定程度上降低基體中鎂原子的過飽和度，可使穩(wěn)定化退火態(tài)5E06鋁板在長期使用過程中晶間腐蝕性能不發(fā)生明顯退化。
關(guān)鍵字: 冷變形；穩(wěn)定化退火；5E06鋁合金；晶間腐蝕；敏化；β相
（1. School of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China；
2. Materials and Technology Research Institute, Dongfeng Commercial Vehicle Technical Center, Wuhan 430056, China）
Abstract:The effects of cold deformation and annealing on the intergranular corrosion property of 5E06 aluminium alloy plates were investigated by intergranular corrosion property tests and transmission electron microscope (TEM). The results show that the intergranular corrosion property of 5E06 aluminium alloy plates has close relationship with the distribution, morphology and quantity of β phase. When the cold deformation is under 40%, β phase is easy to precipitate continuously at grain boundaries which will worsen the intergranular corrosion property. When the cold deformation exceeds 55%, β phase is not easy to achieve succession after stabilizing annealing and the 5E06 aluminum alloy plates have favorable intergranular corrosion property. Sensitization tests indicate that the effect of stabilizing at 120 ℃ is not desirable for 5E06 aluminum alloy plates at cold deformation of 55%-80%, whereas the aluminum alloy plates annealed at 220 ℃ can obtain homogeneous subgrains and β phase distributes discretely at grain boundaries and subgrain boundaries which can reduce the degree of supersaturation to some extent. Therefore, the intergranular corrosion property of 5E06 aluminum alloy plates at stabilizing annealing states won’t degenerate obviously in the long-term using process.
Key words: cold deformation; stabilizing annealing; 5E06 aluminium alloy; intergranular corrosion; sensitization; β phase
