Effect of Solute Elements on Boron Segregation in Boron-Containing Steels
Effect of Solute Elements on Boron Segregation in Boron-Containing Steels
复制标题
溶质元素对含硼钢中硼偏析的影响
作者：
K. Luitjohan;M. Krane;D. Johnson
少量的硼，在0.002%到0.005%之间，可以增加钢的淬透性。1)然而，添加硼也使钢的商业化生产变得困难，特别是通过连铸。产生的铸件缺陷包括表面裂纹、内部中途裂纹和铸件漏损。2)铸件缺陷的来源预计源于变晶反应。3)基于前人的实验工作，变晶反应发生在0.0025和~0.06wt%B之间的二元系中，温度为~1385°C.4)当碳添加到铁和硼中时，变晶反应被预测为δ→L+γ。5，6)具有0.05wt%C时，变晶反应发生在例如，TCFE8热力学数据库(Thermo-Calc：钢/铁合金数据库)预测，在1420°C和1458°C之间的温度下，将发生0.002至0.0055 wt%B的变晶反应，如图1(A)所示。5，6)随着碳含量的增加，预测的变晶反应的组成范围缩小，最终在0.2wt%C左右消失，图1(B)。除溶质元素对含硼钢硼偏析的影响外
Small amounts of boron, between 0.002 and 0.005 wt%, can increase the hardenability of steel alloys.1) However, the addition of boron also makes the steel difficult to commercially produce, specifically via continuous casting. The casting defects that develop include surface cracks, internal half-way cracks, and casting breakouts.2) The source of the casting defects are anticipated to stem from a metatectic reaction. In the binary iron-boron system, a metatectic reaction, δ → L + γ , occurs resulting in a solid piece of material locally remelting as it cools.3) Based on previous experimental work, the metatectic reaction occurs in the binary system between 0.0025 and ~0.06 wt% B at ~1 385°C.4) When carbon is added to iron and boron, the metatectic reaction is predicted to occur as δ + γ → L + γ .5,6) With 0.05 wt% C, for example, the TCFE8 thermodynamic database (Thermo-Calc: Steels/Fe alloys database) predicts a metatectic reaction to occur from 0.002 to 0.0055 wt% B at temperatures between 1 420°C and 1 458°C, shown in Fig. 1(a).5,6) As the carbon content increases, the composition range of the predicted metatectic reaction shrinks, eventually disappearing around 0.2 wt% C, Fig. 1(b). Aside from Effect of Solute Elements on Boron Segregation in Boron-Containing Steels