不同工艺下低碳马氏体钢的组织与力学性能

研究了淬火温度和保温时间对低碳马氏体钢组织、抗拉强度和屈服强度的影响.结果表明,淬火温度和保温时间对试样的组织和力学性能影响显著;在890℃下保温70和210 s淬火试样的组织主要为板条状马氏体和块状铁素体;在920和950℃下保温210 s淬火,其组织为板条状全马氏体;在920℃下保温70～210 s淬火试样具有良好的力学性能.

Preparation and sintering properties of zirconia-mullite-corundum composites using fly ash and zircon

Zirconia-mullite-corundum composites were successfully prepared from fly ash,zircon and alumina powder by a reaction sintering process.The phase and microstructure evolutions of the composite synthesized at desired temperatures of 1 400,1 500 and 1 600°C for 4 h were characterized by X-ray diffractometry and scanning electronic microscopy,respectively.The influences of sintering temperature on shrinkage ratio,apparent porosity and bulk density of the synthesized composite were investigated.The formation process of the composites was discussed in detail.The results show that the zirconia-mullite-corundum composites with good sintering properties can be prepared at 1 600°C for 4 h.Zirconia particles can be homogeneously distributed in mullite matrix,and the zirconia particles are around 5μm.The formation process of zirconia-mullite-corundum composites consists of decomposition of zircon and mullitization process.

50t转炉静态控制模型开发及生产实践

以物料平衡和热平衡为理论基础,开发了转炉炼钢静态控制模型,应用于50 t转炉进行生产实践。结果表明:通过模型计算指导转炉加料及供氧操作,冶炼过程比较平稳、喷溅率大幅度降低、终点钢渣成分趋于稳定,达到了规范操作、降低炼钢成本和稳定产品质量的目的。

提高转炉出钢碳含量的生产实践研究

转炉采用终点低拉碳法生产中高碳钢，钢水氧含量高，后续脱氧难度大、钢中夹杂物多。基于降低生产成本和提高钢水洁净度的双重目的，进行了提高中高碳钢出钢碳含量的可行性分析及生产实践。通过优化供氧枪位和改进加料方案，实现了吹炼前期高效脱磷、中后期强化脱磷并抑制脱碳，将转炉单渣操作的出钢碳含量由原来的平均0．06％提高到0．10％-0．20％范围内，钢水磷含量控制在0．016％以下。

掺杂sc的CaZrO_3的制备及电学性能

采用掺杂Sc_2O_3,通过固相反应法制备了CaZr_(1-x)Sc_xO_(3-α)(x=0,0.1,0.15)材料.在610-850℃采用交流阻抗谱法测定了CaZr_(1-x)Sc_xO_(3-α)的电导率及电导激活能,并对CaZrO_3掺Sc及掺In样品的电学性能进行了比较.结果表明:在610-850℃,CaZrO_3的电导率为4.3×10^(-19)-1.4×10^(-6)S/cm,CaZr_(1-x)Sc_xO_(3-α)(x=0.1,0.15)的电导率为1.16×10^(-4)-1.4×10^(-3)S/cm,CaZr_(1-x)In_xO_(3-α)(x=0.1,0.15)的电导率为0.34×10^(-4)-4.33×10^(-4)S/cm,且随着温度的升高而提高;掺杂能极大提高CaZrO_3的电导率,并随着掺杂量的增加,电导激活能降低,电导率增加;温度及掺杂量相同时,掺Sc材料电导率明显高于掺In材料,说明掺Sc对提高材料的电导率更有效.