( 1. 東北大學(xué) 材料與冶金學(xué)院，沈陽(yáng) 110004；
2. 山東輕工業(yè)學(xué)院 機(jī)電工程學(xué)院, 濟(jì)南 250100)
摘 要: 通過(guò)硬度、 拉伸和成形性實(shí)驗(yàn)及透射電鏡、 掃描電鏡、 能譜和金相分析， 研究了Mg、 Si和Mn含量的變化對(duì)6000系汽車板鋁合金的顯微組織、 力學(xué)性能及成形性的影響， 并探討適宜的預(yù)時(shí)效處理工藝。 研究結(jié)果表明： 提高合金中的Mn含量， 可增加合金中不可溶結(jié)晶相及彌散相粒子的數(shù)量， 前者對(duì)合金的延伸率不利， 后者阻礙了合金固溶處理過(guò)程中的再結(jié)晶。對(duì)于Si過(guò)剩的合金， 提高合金中Mg和Si的質(zhì)量比和Mn含量會(huì)使其強(qiáng)度升高， 延伸率、 應(yīng)變硬化指數(shù)、 塑性應(yīng)變比和埃利克森值被降低。合金板材固溶處理水淬后立即預(yù)時(shí)效， 較為適宜的預(yù)時(shí)效（固溶處理后立即在170 ℃下進(jìn)行5～10 min的短時(shí)預(yù)時(shí)效）不僅能降低其自然時(shí)效的硬度， 而且能提高人工時(shí)效的硬化效果， 有利于車身構(gòu)件的沖壓成形和烤漆硬化能力的提高。
關(guān)鍵字: 6000系鋁合金； 汽車板； 預(yù)時(shí)效； 硬度； 烤漆硬化
6000 series aluminium alloys for automotive body sheets
ZUO Liang1
（ 1. School of Materials and Metallurgy,
Northeastern University, Shenyang 110004, China;
2. School of Mechanical and Electrical Engineering,
Shandong Institute of Light Industry, Jinan 250100, China）
Abstract: Through transmission electron microscope, scan electron microscope, energy spectrum, metallograph analysis and hardness, tensile and formability tests, the effects of Mg, Si and Mn contents variation on the microstructures, tensile properties and formability of a few 6000 series aluminium alloys for automobile body sheets were investigated, the suitable pre-aging treatment technology was also researched. The results show that the number of insoluble constituents and dispersoid particles in alloys increase with increase of Mn content, the former is detrimental for the specific elongation of alloys, and the latter impedes recrystallization during solution treatment. For Si alloys excess, the strength is enhanced, and the specific elongation, strain hardening exponent, plastic strain ratio and Erichsen value, are decreased with Mg and Si mass ratio and Mn content increasing. Pre-aging of alloy sheets immediately after solution treatment and quenching can not only reduce the hardness of subsequently natural aging, but also enhance the hardening effect of following artificial aging, which is advantage to stampping formation and hardenability increasing during paint bake cycle. The suitable pre-aging treatment system is the short-time pre-aging at 170 ℃ for 5-10 min immediately after solution treatment.
Key words: 6000 series aluminium alloys; automotive body sheets; pre-aging; hardness; paint bake hardenability
