Abstract

Under conditions of converter shop of JSC “ArcelorMittal Temirtau”, the authors have developed and implemented the direct microalloying technology of structural steels with boron. Microalloying was carried out due to boron recovery from the slags of the CaO–SiO₂–B₂O₃–MgO–Al₂O₃ system formed in ladle furnaces. The use of the developed technology was provided in steels 08KP, 3SP, 3PS and 09G2S boron content of 0.0016–0.0050%, with a sufficiently high degree of metal desulfurization 36.8–51.7% and reduction in manganese ferroalloys consumption by 0.3–0.6 kg/t of steel, which improved the environmental situation by eliminating the use of fluorspar. For 09G2S steel, the yield σ_y and tensile σ_t strengths are higher for the experimental metal then for the steel without boron by an average 27 and 24 MPa, respectively. The elongation percentage of the metal with boron increased by an average 0.2%. The grain-size index of rolled metal of 08KP steel with a thickness of 2.0–2.5 mm, containing 0.001% of boron and a manganese concentration lowered to 0.18%, reaches 10.0 in contrast to 9.0 for the heats of the current production. The yield σ_y and tensile σ_t strengths are on average by 6.0 and 5.0 MPa higher for an experimental metal than for a comparative one. The percentage of elongation δ reaches 36.3% for the experimental metal unlike 33.3% for the heats of the current production. Experimental rolled metal of 3PС steel with lower concentration of manganese lowered by 0.02%, as well as with an average boron content of 0.001%, is characterized by an increased yield strength σ_y, tensile strength σ_t (on average by 2.0 and 9.0 MPa) and percentage of elongation δ reaching an average of 21.0% with fine-grained structure. The rolled metal of 3SP steel, microalloyed with boron and with a 4-mm thickness that contains manganese content reduced to 0.43%, is characterized by improved strength properties with preservation of plastic characteristics. The absolute value of the yield σ_y and tensile σ_t strengths of steel are by 4.0 and 2.0 MPa higher than the strength characteristics of steel without boron.

中文翻译：

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含硼结构钢直接微合金化对其结构和力学性能的影响

摘要

在股份公司“ ArcelorMittal Temirtau”的转炉车间条件下，作者开发并实施了含硼结构钢的直接微合金化技术。由于从钢包炉中形成的CaO-SiO ₂ -B ₂ O ₃ -MgO-Al ₂ O ₃系统的炉渣中回收了硼，因此进行了微合金化。钢08KP，3SP，3PS和09G2S的硼含量为0.0016-0.0050％，金属脱硫率很高，为36.8-51.7％，锰铁合金的消耗降低了0.3-0.6 kg / t，使用了开发的技术钢铁，从而消除了使用氟石的使用，从而改善了环境状况。对于09G2S钢，产率σ _ÿ实验金属的抗拉强度和抗拉强度_{t t}分别比不含硼的钢高出平均27 MPa和24 MPa。金属与硼的伸长百分比平均增加0.2％。对于当前生产的热量，厚度为2.0–2.5毫米，含0.001％的硼和锰含量降低至0.18％的08KP钢的轧制金属的晶粒度指数达到10.0，而9.0。产率σ _ÿ和拉伸σ_吨实验金属的强度平均比对比金属高6.0和5.0 MPa。实验金属的伸长率δ达到36.3％，而目前生产的热量的伸长率δ达到33.3％。实验轧制3PС钢的金属与由0.02％降低的锰浓度较低，以及与0.001％的平均硼含量的特征在于增加的屈服强度σ _ÿ，拉伸强度σ_吨（平均2.0和9.0 MPa），伸长率δ的平均百分比达到21.0％（具有细粒结构）。硼微合金化的3SP钢的轧制金属，其4毫米厚的锰含量降低至0.43％，其特点是强度特性得到改善，同时保持了塑性。产率σ的绝对值_ÿ和拉伸σ_吨钢的强度为4.0和2.0兆帕比钢的强度特性不含硼高。