连铸全保护浇注工艺的优化

结合川威连铸生产实际,通过探索、研究全保护浇注优化的措施和手段,不断完善全连铸保护浇注工艺,提高连铸机各项技术经济指标。     

Casting guidelines, tips, and techniques: proceedings from the 1997 American Burn Association PT/OT Casting Workshop

Approximately 100 therapists attended the PT/OT Casting Workshop at the twenty-ninth Annual Meeting of the American Burn Association in New York City, N.Y., on March 20, 1997. The workshop consisted of four groups: two demonstrating hand/wrist casting and two demonstrating casting of the foot/ankle. Participants had the opportunity to attend one upper extremity group and one lower extremity group lasting approximately 50 minutes each. Instructors provided a demonstration of a casting procedure while addressing general guidelines, indications, contraindications, and precautions related to casting each area. Thorough handouts were provided, and each participant had the opportunity to apply two casts. The following article is a compilation of the four handouts and their bibliographies.     

拉速对结晶器平均热流的影响

通过计算8088块板坯的平均热汉研究了拉速对板坯结晶器平均热流的影响结果表明：拉速对结晶器宽边的平均热流有显的影响,拉速在0．6－1．2m/min范围内,结晶器宽边平均热流随拉速提高而增加,当拉速超过1．2m/min后,结晶器宽边平均热流随拉速增加而提高的幅度变得很小;结晶器窄边的平均热流较宽边的热流约低0．2MW／m^2,当拉速超过1．2m/min后,结晶器窄边的平均热流仍可随拉速的进一步提高而增加。     

连铸圆管坯轧管和钢管的连铸连轧

研究了连续圆管坯轧管中的铸坯质量、轧制工艺和压缩比等三个主要问题，在此基础上，介绍了国外钢管连铸连轧和近终形技术的发展概况，并对发展我国的钢管连铸连轧技术进行了讨论。     

Melting,Remelting, and Casting for Clean Steel

The control of the metallurgy of steels is now highly developed. This is in contrast to the casting techniques for steels. Although continuous casting is generally conducted well, current ingot casting techniques are poor, unnecessarily introducing masses of oxides. For some steel compositions, double oxide films, bifilms, are entrained. This mechanism, occurring naturally during pouring, but till now generally overlooked, appears to be capable of explaining most of the features of steel defects in all their forms. For most Ni alloys and some steels it appears capable of generating a dense population of cracks, greatly impairing subsequent mechanical working and even final properties. In other steels the effects are much less severe. The techniques to avoid this damage to liquid steels and Ni alloys are described, including contact pouring, and naturally pressurized filling system designs. An ultimate system is counter gravity casting. For remelting processes, the risks of unreliability because of cracks intrinsic to VIM and VAR are discussed for both shop floor production and laboratory research. The potential crack‐free properties of ESR when correctly made are recommended. Even so, remelting processes might constitute an unnecessary luxury if steels and Ni alloys were cast to avoid the entrainment of oxides.     

TP2管坯水平连铸及其拉铸系统程序设计

水平连铸TP2紫铜管是铸轧法生产优质空调管坯的第一步工艺。依据对铸造理论的铸造温度、铸造速度和冷却强度三要素工艺研究,结合科尔摩根伺服系统特性,优化设计出水平连铸TP2铜管坯新拉铸工艺程序。     

大方坯中低碳钢连铸保护渣研制与应用

在借鉴国内外研究经验的基础上,结合攀钢中低碳钢方坯连铸工艺条件,在实验室进行了保护渣结晶与玻璃化特性协调、吸收夹杂物能力及配碳模式等方面的研究,确定了合理的渣系及物理性能、化学成分.工业试验结果表明,研制的保护渣能够满足工艺要求,可以取代进口保护渣.     

异形坯连铸机保护浇注生产实践及分析

以Q345B级H型钢生产工艺为基础,对莱钢异形坯连铸机双注流保护浇注和敞开浇注方式对生产的影响、生产的铸坯及轧材质量等进行了分析对比。结果表明,保护浇注的流场、温度场等无明显变化,铸坯质量良好,与敞开浇注相比,在其他工艺相同的情况下,保护浇注方式生产的型钢中气体含量减少10×10-6,夹杂物总量减少45.5%。     

Experimental Determination of Heat Transfer Within the Metal/Mold Gap in a DC Casting Mold: Part II. Effect of Casting Metal, Mold Material, and Other Casting Parameters

Extensive experimental studies were conducted to quantify the effect of different parameters that can affect the heat transfer from the metal to the mold during the steady-state phase of DC casting. In the first part previously published, the experimental technique was established and results were reported for the effect of gas type (atmosphere within the mold) and the gap between the metal and the mold. The results showed the significant effect of gas thermal conductivity and the metal-mold gap on the mold wall heat transfer coefficient. In this second publication on heat transfer in the mold wall region of a DC casting mold, the results from the effect of casting temperature, gas flow rate, casting alloy, mold material, and the mold insert material on the mold wall heat transfer coefficient are described. The experiments reported in the current paper show that these additional factors tested do not affect the heat flux through the mold wall to the same extent as the gap size or the gas type. The heat transfer coefficient changes by less than 5 pct when casting temperature is changed by ±25 K, less than 15 pct when the gas flow rate within the metal-mold gap flows at up to 3 LPM, and approximately 30 pct when the mold material is changed from stainless steel to AA601 to copper. Similar results were obtained when different insert materials were used. These results are explained with the help of an electrical analogy of heat transfer and are consistent with the heat transfer theory.     

铸造模拟对几种典型铸件的工艺改进

利用Anycasting分析软件对铸造行业中几种典型铸件进行充型凝固耦合分析,通过实践经验证明了铸造模拟仿真技术在铸造过程中对工艺方案的改进及成本的降低所起的积极作用。     

金属半固态铸造成形技术

金属的半固态铸造是近年来出现的一种新的铸造加工成形方法。该方法与传统的全液态铸造相比，具有节约能源、生产率高、产品质量好等优点。本文介绍了半固态金属浆料的制备方法，半固态压铸、半固态连铸等金属半固态铸造成形技术，并指出了存在的问题及进一步研究工作。     

保护浇注在连铸生产中的实践

通过生产实践，讨论了连铸机保护浇注在推广应用中的措施，阐述了保护浇注对提高铸坯质量所起的作用。     

特殊钢的连铸

特殊钢一般含有一定的合金元素,冷却凝固状态不同于普通碳素钢,在连铸坯中更易产生成分 和组织偏析,和表面裂纹等缺陷。所以冶炼特殊钢时应提高钢水的纯洁度,减少夹杂物含量和改善夹杂物形 态,连铸时采用钢液二次氧化和污染,以减少铸坯低过热度(10～15℃)浇注和保护浇铸技术,防止成分和组 织偏析,提高铸坯表面质量和内部致密度。叙述了连铸保护浇铸技术,中间包冶金,电磁搅拌、凝固末端轻压 下特殊钢连铸专用覆盖剂、保护渣和自动化技术。讨论了特殊钢连铸工艺参数,存在的问题和对策。     

高拉速连铸结晶器非正弦振动同步控制模型

 结晶器非正弦振动是实施高拉速连铸和提高铸坯质量的关键技术。提出了结晶器非正弦振动波形及振动工艺参数的确定方法和基本参数的选取原则,并结合高拉速连铸机的特点,分析了振动基本参数对工艺参数的影响规律,建立了拉速与振动基本参数间的同步控制关系,为改善工艺参数、最大限度地发挥非正弦振动技术优势、满足高效连铸生产要求提供了依据和指导。     

连铸技术发展

简要评述了我国连铸技术的发展概况，传统连铸技术的发展，薄板坯连铸技术发展以及薄带坯连铸技术发展。对提高连铸机生产率和连铸坯质量的技术措施进行了讨论。     

迁钢板坯恒拉速技术应用与实践

炼钢系统是离散-连续的过程,整个系统的设备较多且操作变数大,实现常规板坯恒定拉速连续铸钢的关键是铁水预处理、转炉炼钢、钢水二次精炼、板坯连铸等环节间的钢水物质流、温度变化的能量流、生产节奏的时间流的传递,恒拉速实施过程中要求设备平稳运行、生产工艺科学合理、生产节奏平稳有序等一系列稳定条件,同时还要做到“时时、班班”相同。迁钢炼钢厂在实行板坯恒拉速技术开发与应用过程中,以优化各工序生产工艺,加强过程控制能力,科学、稳定、高效组织生产为手段,恒拉速率已经连续49个月稳定在97%以上,创造了1 000万t 连续不漏钢的记录。     

提高连铸生产能力的措施与效果

铁水增多所导致的转炉生产节奏加快以及连铸机改造后差异性的扩大,使宝钢分公司第一连铸分厂的产能压力和生产组织难度增大。为此,优化了连铸生产组织,并从连铸机生产计划的分工、工序和生产线交叉、特殊钢种的生产组织、中间包利用最大化、浇铸速度和异钢种连浇的优化等方面,提出了提高连铸产能的措施,且实施后取得了明显效果,连铸日浇钢增加了2.4炉。     

Effect of Casting Speed on Slab Broadening in Continuous Casting

A three‐dimensional viscoelastic‐plastic thermal‐mechanical coupled finite element model was based on the basis of the secondary development of commercial software (MSC, Marc software, USA) to simulation the effect of casting speed on slab broadening in the secondary cooling zone. The results show that the ratio of ultimate broadening increased with increasing casting speed for various steel grades, but the change in broadening lagged that in casting speed. When the casting speeds were 1.0 m/min, 1.1 m/min, and 1.2 m/min for Q235 steel, the maximum ratios of ultimate broadening were 1.52%, 1.59%, and 1.81%, respectively, and the average ratios of ultimate broadening at the exit of the caster were 1.00%, 1.27%, and 1.48%, respectively; for SPHC steel, the maximum ratios of ultimate broadening were 1.34%, 1.44%, and 1.69%, respectively, and the average ratios of ultimate broadening at the exit of the caster were 0.64%, 0.76%, and 0.95%, respectively. The simulation results were verified by measurements on an SMS‐Demag continuous caster of Maanshan Iron and Steel Co. Ltd.; the measurement results agree with the simulation results. The mechanism of the effect of casting speed on slab broadening was also analyzed.     

铜圆盘定量浇铸系统故障分析与排查

文章简要介绍了铜圆盘浇铸机定量浇铸系统的基本构造及工作原理,阐述了定量浇铸系统出现仪表无显示、定量浇铸电子秤不浇铸、定量浇铸电子秤浇铸时不返回、工控机显示浇铸重量与实际重量不相符、浇铸时与返回后显示重量偏差不一致、浇铸时显示数值出现波动等常见故障的排查处理措施.     

提高连铸生产能力的措施与效果

铁水增多所导致的转炉生产节奏加快以及连铸机改造后差异性的扩大,使宝钢分公司第一连铸分厂的产能压力和生产组织难度增大。为此,优化了连铸生产组织,并从连铸机生产计划的分工、工序和生产线交叉、特殊钢种的生产组织、中间包利用最大化、浇铸速度和异钢种连浇的优化等方面,提出了提高连铸产能的措施,且实施后取得了明显效果,连铸日浇钢增加了2.4炉。