(1.中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；
2.蘇州大學(xué) 沙鋼鋼鐵學(xué)院，蘇州 215006)
摘 要: 結(jié)合金相顯微鏡(OM)、電子背散射衍射技術(shù)(EBSD)等來分析Cr、Mn質(zhì)量比對Al-Mg-Si合金在變形溫度400~560 ℃、應(yīng)變速率0.3 s-1的單軸壓縮實驗下的變形行為以及組織的影響。結(jié)果表明：在同一變形條件下，合金中Cr、Mn質(zhì)量比越大，合金的峰值流變應(yīng)力越大。在高溫變形時，發(fā)生的動態(tài)軟化主要為動態(tài)回復(fù)(DRV)和部分動態(tài)再結(jié)晶(DRX)。不同Cr、Mn質(zhì)量比阻礙合金發(fā)生DRV/DRX的程度不同，其中0.5CrMn合金阻礙程度最大。在熱變形過程中，亞晶尺寸與穩(wěn)態(tài)流變應(yīng)力相關(guān)，且穩(wěn)態(tài)流變應(yīng)力與亞晶尺寸的倒數(shù)呈線性關(guān)系。
關(guān)鍵字: Al-Mg-Si合金；熱變形；動態(tài)回復(fù)；動態(tài)再結(jié)晶；亞晶尺寸
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. School of Iron and Steel, Soochow University, Suzhou 215006, China）
Abstract:The hot deformation behaviors and microstructural evolution of Al-Mg-Si alloys containing different mass ratio of Cr to Mn (0.1-0.5) under the uniaxial compression tests at temperature range of 400-560 ℃ and strain rate of 0.3 s-1 were investigated by optical microscopy (OM) and electron back-scattering diffractometry (EBSD). The results show that the peak flow stress increases with increasing the mass ratio of Cr to Mn under the same deformation conditions. Under the high-temperature deformation, the main softening mechanisms are dynamic recovery (DRV) and dynamic recrystallization (DRX). The extent of DRV and DRX is related to the mass ratio of Cr to Mn and the 0.5CrMn alloy shows the strongest inhibition effect. During the hot deformation, the relationship between steady-state flow stress and reciprocal subgrain size presents a good linear relationship.
Key words: Al-Mg-Si alloys; hot deformation; dynamic recovery; dynamic recrystallization; subgrain size
