(1. 中南大學 材料科學與工程學院，長沙 410083；
2. 中南大學 有色金屬材料科學與工程教育部重點實驗室，長沙 410083；
3. 山東南山鋁業(yè)股份有限公司 國家鋁合金壓力加工工程技術(shù)中心，龍口 265700)
摘 要: 研究固溶溫度(480~580 ℃)對6082鋁合金擠壓板材的力學性能和晶間腐蝕性能的影響規(guī)律，結(jié)合金相顯微鏡、掃描電鏡和掃描透射電鏡對影響機理進行分析。結(jié)果表明：隨著固溶溫度的升高，合金的強度先升高后下降，在520~540 ℃時達到最高值；而伸長率呈現(xiàn)不斷升高的趨勢；晶間腐蝕的最大深度呈現(xiàn)先增加后降低的趨勢。隨著固溶溫度的升高，殘留結(jié)晶相的數(shù)量逐漸減少，時效后獲得的β″沉淀強化相的尺寸更小、密度更高，晶界無沉淀析出區(qū)更窄，強度和伸長率更高；但溫度過高時，再結(jié)晶嚴重，晶粒粗大，擠壓效應(yīng)消失，強度下降。固溶溫度影響再結(jié)晶和亞晶粒大小以及晶界第二相析出狀態(tài)和無沉淀析出帶寬度，進而改變晶間腐蝕擴展路徑及最大腐蝕深度。
關(guān)鍵字: 6082鋁合金；固溶處理；力學性能；晶間腐蝕；顯微組織
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metals Science and Engineering, Ministry of Education,
Central South University, Changsha 410083, China;
3. National Engineering Research Center for Plastic Working of Aluminum Alloys,
Shandong Nanshan Aluminum Co., Ltd. Longkou 265700, China）
Abstract:The effect of solution heat treatment temperature on the mechanical properties and intergranular corrosion of the extruded sheets of 6082 aluminum alloy was investigated and the mechanism was discussed based on the microstructure examination by optical microscopy, scanning electron microscopy and scanning transmission electron microscopy. With the increase of temperature, the strength increases firstly to the maximum value at 520-540 ℃, then, decreases; while the elongation increases gradually; the maximum penetration depth of intergranular corrosion increases firstly, then, decreases. The increase of temperature tends to decrease the number of remnant phases and results in smaller β″ hardening precipitates with a higher density and consequently higher strength. However, too high temperatures result in coarse recrystallized grains, and thus, extrusion effect disappears and the strength decreases significantly. Solution heat treatment temperature has great effect on the recrystallization and size of subgrains, particles at grain boundaries and width of precipitates free zone adjacent to grain boundaries, therefore, changes the penetration path of IGC (Intergranular corrosion, IGC) and the maximum penetration depth.
Key words: 6082 aluminum alloy; solution heat treatment; mechanical property; intergranular corrosion; microstructure
