钢包底吹氩吹通率攻关实践

分析了吹不通铡包底的原因,提出了提高底吹氩吹通率的措施,并使其达到99．8％以上。     

铆螺钢冷镦开裂的分析和精炼工艺的改进

采用铁水预处理-LD-钢包吹氩工艺生产铆螺钢,通过对0.23%C~0.69%Mn铆螺钢冷镦开裂组织和夹杂物的扫描电镜和能谱分析得出,钢中存在多种元素复合夹杂物是铆螺钢冷镦开裂的主要原因。通过将钢包底吹氩压力由0.3 MPa提高到0.6~1.0 MPa,并由原工艺吹氩1 min后软吹氩、总吹氩时间为3 min改为吹氩3 min后软吹氩、保证总吹氩时间≥6 min,同时改进中间包烘烤工艺减少MgO夹杂,从而有效地避免了铆螺钢冷镦时的开裂现象。     

液氩泵机械故障分析

详细介绍液氩泵解体检查的情况,分析液氩泵转子铜质双头螺柱断裂和铜压块磨损的原因,最后阐述了液氩泵的操作经验。     

Effect of the carrier gas on the metal-organic chemical vapor deposition of TiN from tetrakis-dimethyl-amido-titanium

The effect of carrier gas such as hydrogen, nitrogen and argon on the deposition rate, film morphology, resistivity and chemical composition of TiN film from tetrakis-dimethyl-amido-titanium (TDMAT) was studied. The deposition rate was higher with argon and nitrogen and lower with hydrogen when the substrate temperature was above 300°C. The surface morphology of the film deposited with hydrogen carrier gas was rough due to the gas phase reaction. The film deposited at the higher substrate temperature with hydrogen had higher resistivity than in the film deposited with argon or nitrogen due to the rough surface.     

7500m~3/h空分设备全精馏无氢制氩系统改造

壁流效应是影响规整填料氩塔精馏效果的主要因素之一,壁流效应严重程度不同、发生的位置不同,影响也不同。通过分析壁流效应对规整填料的影响,并利用反馈计算,成功地对一套全精馏无氢制氩系统进行了改造,使工艺氩氧含量大大降低,达到改造目的。     

200 t LD-LBAr-CC流程生产低碳铝镇静钢的洁净度

钢厂试验的低碳铝镇静钢(/%:0.036～0.037C、0.009Si、0.173～0.176Mn、0.012～0.013P、0.005～0.006S)生产流程为200 t LD转炉-钢包吹Ar精炼(LBAr)-230 mm×1 300 mm板坯连铸工艺。通过LD转炉挡渣出钢,并加入Mn-Fe、铝丸进行预脱氧和合金化3 min,钢水T[O]和[N]分别为91.8×10^-6和19.4×10^-6,在氩站经10～12 min 25～45 m³/h流量吹氩和3～5 min 15～25 m³/h的软吹氩后,T[O]降至42.3×10^-6,[N]为22.0×10^-6,中间包和铸坯T[O]分别为38.3×10^-6和28.9×10^-6,[N]分别为23.6×10^-6和26.5×10^-6。该流程生产的铸坯满足T[O]≤30×10^-6的内控要求。经氩站精炼后,显微夹杂物去除率为30.0%,而大型夹杂物去除率达58.7%;显微夹杂物主要为脱氧产物Al₂O₃;大型夹杂物主要为SiO₂、Al₂O₃、SiO₂-Al₂O₃、CaO-SiO₂-Al₂O₃。     

130 t钢包底吹氩喷嘴布置模式优化的水模型试验

通过建立的130t钢包水力学模型，用电导法测定了单喷嘴、双喷嘴垂直分布和对称分布时不同供气量下钢水混匀时间。结果表明，双喷嘴喷吹的混匀时间较单喷嘴的混匀时间短，搅拌效果优于单喷嘴。单喷嘴底吹氩，喷嘴距钢包底部中心0．55R（钢包底半径）时混匀时间最短；双喷嘴间距由0．40R增至0．70R时混匀时间明显减少。     

高洁净MCrAlY合金粉末的制备及涂层性能

采用VIGA 16真空氩气雾化设备制取MCrAlY粉末,制取的粉末经处理后,用LPPS-TF工艺喷涂制备高性能涂层。结果表明,真空氩气制取的粉末氧、氮、氢含量较低,且以球形为主,具有良好的流动性,杂质碳、氮、氢含量低等特征。原料全部为新料时可制备出氧含量最低达125×10~(-6)的粉末,经过处理后,粉末中的陶瓷夹杂总数在3个/(100g)以下。用LPPS-TF工艺制取的涂层结构致密,氧含量低,涂层与基体结合达到81.3MPa。     

Potential of VHF-plasmas for low-cost production of a-Si: H solar cells

Compared to the use of the standard glow discharge technique the production of amorphous silicon solar cells by the very high frequency glow discharge (VHF-GD) bears yet additional cost reduction potentials:Using VHF-GD at excitation frequencies higher than 13.56 MHz, a more efficient dissociation of silane gas is obtained; thus, higher deposition rates are achieved; this reduces considerably the deposition time for intrinsic amorphous and microcrystalline silicon layers.Furthermore, by itself and even more so, in combination with argon dilution, VHF-GD technique improves silane utilisation and leads, thus, to further cost reduction.Finally, by combining the VHF-GD technique and the “micromorph” concept “real” tandem cells (i.e. a superposition of two cells with distinctly different band gaps) can be deposited at low temperatures without the use of expensive germane gas.     

低温法空气分离的进展

通过对目前低温法空分流程的分析,可以找到其节能优化的途经。对空分主精馏塔的上塔和氩塔采用规整填料是目前此领域的一个新动向。天津大学和开封空分设备厂在3200NM~3/h装置上的改造实践,取得了成功。