Abstract This study reports on ultra-high temperature tensile tests (1300–1480 ∘C) performed on dual-phase (DP) advanced high-strength steels utilizing a Gleeble 3500 thermo-mechanical simulator The thermomechanical results of both as-cast (AC) and transfer-bar (TB) materials are presented, as well as three different sample geometries, to better comprehend the effect of temperature distribution and stress localization on the reproducibility of data. The results show that presence of pre-existing porosity in the AC structure decreases the ultra-high temperature strength of the material because of voids nucleation, growth and coalescence, while tearing apart of the melt in highly susceptible zones plays an important role to drastically increase the ultra-high temperature embrittlement of the TB material. It is shown that a sample with long-gauge-length (LGL) geometry provides the most consistent reproducibility as compared with other geometries; this is attributed to a combination between gentle stress localization and intensified temperature distribution along the gauge length.

中文翻译：

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DP600高级高强钢连铸及中间棒组织热脆化研究

摘要 本研究报告了使用 Gleeble 3500 热机械模拟器对双相 (DP) 高级高强度钢进行的超高温拉伸试验 (1300–1480 ∘C) 两种铸态 (AC) 的热机械结果介绍和传输杆 (TB) 材料，以及三种不同的样品几何形状，以更好地理解温度分布和应力定位对数据再现性的影响。结果表明，由于空隙的成核、生长和聚结，AC 结构中预先存在的孔隙的存在降低了材料的超高温强度，而在高度敏感区的熔体撕裂对急剧增加起着重要作用。 TB材料的超高温脆化。结果表明，与其他几何形状相比，具有长标距 (LGL) 几何形状的样品可提供最一致的再现性；这归因于温和的应力局部化和沿标距长度的强化温度分布之间的结合。