(北京科技大學 新材料技術(shù)研究院，北京 100083)
摘 要: 采用熱冷組合鑄型(HCCM)水平連鑄制備橫斷面尺寸70 mm×10 mm(寬度×厚度)具有強軸向取向柱狀晶組織的純銅板坯，研究工藝參數(shù)對純銅板坯微觀組織、表面質(zhì)量與力學性能的影響。結(jié)果表明：在銅液鑄造溫度1250 ℃，熱型段溫度1100~1150 ℃，冷卻水流量600 L/h、連鑄拉坯速度20~80 mm/min條件下可以制備出表面粗糙度低、具有沿拉坯方向強取向組織和優(yōu)良力學性能的純銅板坯，其抗拉強度為137~141 MPa，斷后伸長率為45.1%~61.7%。隨著拉坯速度的增加，HCCM水平連鑄所制備純銅板坯的組織均勻性增加，晶粒尺寸變小；熱型段溫度升高時板坯的柱狀晶組織的晶界更加平直；而總體上力學性能受拉坯速度和熱型段溫度的影響較小。采用HCCM水平連鑄，在熱型溫度為1150 ℃時制備的純銅板坯的表面粗糙度小于0.3 μm，無需進行銑面可直接進行后續(xù)冷加工，可為發(fā)展銅板帶短流程生產(chǎn)工藝奠定基礎。
關(guān)鍵字: 銅板帶；熱冷組合鑄型；水平連鑄；柱狀晶組織
（Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China）
Abstract:Pure copper slabs with strongly-oriented columnar crystal and 70 mm in width and 10mm in thickness were fabricated by heating-cooling combined mold(HCCM) horizontal continuous casting, and the effects of processing parameters on the microstructure, surface roughness and properties of pure copper slabs were investigated. The results show that pure copper slabs with low surface roughness value and crystal orientation along the casting direction and excellent mechanical properties can be fabricated by HCCM horizontal continuous casting under processing parameters of copper melt temperature 1250 ℃, heating mold temperature 1100-1150 ℃, cooling water flow600 L/h, and casting speed 20-80 mm/min. The tensile strength and elongation after fracture of these copper slabs are in range of from 137 to 141 MPa and from 45.1% to 61.7%, respectively. Increasing casting speed would lead to more uniform structure and finer grain, and the grain boundary of columnar crystal would be more straighter when the temperature of heating-mold rose. However in the whole casting speed and temperature of heating-mold has little influence on the tensile strength and elongation after fracture. The surface roughness value of pure copper slab fabricated by HCCM horizontal continuous casting at the temperature of heating-mold of 1150 ℃ is less than 0.3 μm, which shows that the slab could be directly used to form by rolling without scalping process and be the basis of developing new compact process method of copper strip.
Key words: pure copper slab; heating-cooling combined mold; horizontal continuous casting; columnar crystal
