共查询到18条相似文献,搜索用时 296 毫秒
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为了确定薄带连铸AISI304不锈钢凝固过程中残留铁素体的生成及转变行为,采用彩色金相、电解侵蚀、电子背散射衍射分析技术及X射线衍射分析等研究手段对双辊薄带连铸AISI304不锈钢凝固组织及残留铁素体特征进行了研究.结果表明AISI304不锈钢薄带的凝固组织由表层胞状晶区、中间柱状晶区和中心等轴晶区三部分组成.薄带表层胞状晶区内残留铁素体呈棒状,柱状晶区的残留铁素体形态为鱼骨状,中心等轴晶区的残留铁素体呈弯曲的树枝状;薄带的表层胞状晶区残留铁素体的质量分数为4.6%~6.6%,柱状晶区内的残留铁素体质量分数为3.6%~3.7%,中心等轴晶区内的残留铁素体质量分数为11.27%~11.34%;残留铁素体沿着厚度方向呈现"W"状分布. 相似文献
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双辊法薄带连铸凝固过程热流计算及凝固组织和缺陷形成机理的研究 总被引:6,自引:0,他引:6
文章介绍了双辊法薄带连铸凝固过程热流计算及凝固组织和缺陷的形成机理,为铸造工艺设计,铸带质量分析提供了理论指导,为提高连铸薄带质量提供了提供了可靠的理论依据。 相似文献
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通过工业试验对202不锈钢进行系统取样,分析试样中夹杂物的变化特征,结合热力学计算,研究了202不锈钢中非金属夹杂物的形成机理。在进行硅锰脱氧后,LF精炼过程中钢液内以球型Ca?Si?Mn?O夹杂物为主。对于硅锰脱氧钢,钢液中残余铝质量分数为1×10?5时,可以扩大Mn?Si?O相图的液相区,但铝质量分数超过3×10?5会导致钢中容易形成氧化铝夹杂物并减小液相区。在连铸坯中以Mn?Al?O类夹杂物为主,相较于LF精炼过程试样,连铸坯试样中夹杂物的MnO和Al2O3含量明显增加,CaO和SiO2含量明显减小,夹杂物个数则由LF出钢试样的5.5 mm?2增加到11.3 mm?2。结合热力学计算发现,凝固过程中会有Mn?Al?O夹杂物形成,这也使其成为连铸坯中主要的夹杂物类型。 相似文献
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试验研究了0.000 5%~0.001 2%Mg对60 kg真空感应炉熔炼的430铁素体不锈钢(/%:0.04C、0.25~0.32Si、0.28~0.38Mn、16.5~16.9Cr)夹杂物形成和凝固组织的影响。结果表明,430钢液中添加镁合金后,钢中形成平均粒径更小,数量密度更大的含MgO复合夹杂物;镁合金的加入可以改善430钢的凝固组织,且浇铸温度越低,改善效果越明显,在1 580℃浇铸时,等轴晶率由常规钢的30.8%提高至镁处理钢的88.5%,相应等轴晶尺寸由1 741.6μm降至945.3μm。含MgO夹杂物与δ相二维错配度极小,可作为430钢有效异质形核剂,促进等轴晶的形成,抑制柱状晶的生长,细化凝固组织。 相似文献
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Mirko Javurek Philipp Gittler Roman Rssler Bernhard Kaufmann Hubert Preßlinger 《国际钢铁研究》2005,76(1):64-70
The liquid steel flow and the particle transport of non‐metallic inclusions in the liquid domain inside the strand of a continuous steel casting system are numerically investigated. The whole liquid domain inside the solidified shell is simulated, and the loss of liquid steel due to solidification is considered. Assuming a constant drift velocity, a kind of Euler‐Euler multiphase model is implemented to calculate the inclusion behaviour inside the liquid steel, respectively the inclusion removal at the boundaries. The turbulent flow of the liquid steel and the inclusion behaviour are calculated. The resulting distribution of the inclusions in the slab is compared with measurements. The influence of inclusion size (0 to 1 mm) and casting speed on the inclusion distribution is considered. 相似文献
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反向凝固复合不锈钢带厚度数值计算 总被引:9,自引:0,他引:9
通过建立一维变物性参数凝固传热模型计算了用反向凝固工艺生产复合不锈钢带时钢带的厚度变化,计算结果与实验结果吻合较好,且很好地说明了钢带厚度的变化规律。 相似文献
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The formation and characteristics of non-metallic inclusions in 316L stainless steel produced by the AOD (argon oxygen decarburization)–ladle furnace–continuous casting process were investigated. The morphology and composition of inclusions changed significantly during the refining and casting processes. After de-oxidation with Si/Mn additions, spherical complex inclusions mainly consisting of calcium silicates were observed. The contents of MgO and Al2O3 in these inclusions continuously increased as the steel moved from the AOD through ladle processing to the tundish. As the temperature decreased from the tundish through to solidification, harmful crystals of MgO/Al2O3 spinel were precipitated within the steel melt as well as within the calcium silicate matrix of existing inclusions. The results obtained from thermodynamic calculations carried out using FactSage? commercial software agreed well with the information derived from evaluation of the industrial samples enabling recommendations to be made for the avoidance of detrimental spinel inclusions. 相似文献
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Microstructures and textures of austenitic stainless steel sheets produced by a twin-roll type strip caster are investigated at various stages of casting, cold-rolling and annealing processes. Strip casting is a rapid solidification process and, therefore, the cast strip sheets have fine columnar dendrites and very sharp (100) textures. After cold-rolling and annealing the strip sheets have equiaxial and somewhat finer grains than those produced by the conventional process, and the texture is composed mainly of the (110)[1?2] orientation. 相似文献
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为了研究铝脱氧不锈钢开浇过程中二次氧化对钢水洁净度和夹杂物演变的影响,实现钢中夹杂物的有效控制,分别在LF精炼出站、开浇过程中不同时刻取样,采用扫描电镜、ASPEX自动分析仪、热力学计算等不同方法研究了铝脱氧不锈钢中夹杂物的形貌、成分、数量和尺寸分布,确定了铝脱氧不锈钢开浇过程中夹杂物的演变行为和对应机理。研究结果表明,开浇过程钢中氧氮质量分数、夹杂物数密度变化规律类似,20 min时分别增加至7.4×10?5、0.0674%、17.1 mm?2,此后随着浇铸过程进行逐渐降低;LF精炼出站时钙处理改性夹杂物效果较好,其类型主要为CaO?Al2O3?SiO2?MgO,开浇过程中二次氧化降低了钙处理操作的作用效果,20 min时夹杂物类型转变为MnO?Al2O3?SiO2?CaO复合夹杂物,浇铸约60 min时,连铸过程中钢水的洁净度基本达到稳定,此时夹杂物类型重新转变为CaO?Al2O3?SiO2?MgO;二次氧化使得钢液中氧质量分数较高,促进了MnO?Al2O3-SiO2?CaO夹杂物的生成,而钢中大尺寸的CaO?Al2O3?SiO2?MnO?(MgO)夹杂物主要通过夹杂物间的碰撞聚合形成;凝固过程中随着温度的降低,促进了MgO?Al2O3尖晶石相和CaO?2MgO?8Al2O3相的析出,提高了夹杂物中Al2O3组分的含量。 相似文献