The crystallography and chemistry of interfaces between austenite and ferrite in duplex steels control many important materials properties but remain poorly understood. In this study, we experimentally show that in an additively manufactured and heat treated duplex stainless steel, the majority of austenite-ferrite interfaces terminate on {111}/{110} planes, and this behaviour is more pronounced for rational interfaces with the Kurdjomov-Sachs orientation relationship. Interface segregation was found to be controlled by not only the interface crystallography but also the bonding properties of solute atoms. Solute elements showed higher interfacial excess at irrational interfaces. Furthermore, a heterogeneous distribution of selected solute elements in austenite-ferrite interfaces planes was observed. Our findings reinforce the importance and, in fact, necessity to consider five independent crystallographic parameters and chemical architecture of interphase boundaries for advanced control of mechanical and other critical properties in duplex materials.

中文翻译：

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对增材制造双相不锈钢中奥氏体-铁素体边界特征的新见解

双相钢中奥氏体和铁素体界面的晶体学和化学性质控制着许多重要的材料性能，但人们对其知之甚少。在这项研究中，我们通过实验表明，在增材制造和热处理的双相不锈钢中，大多数奥氏体-铁素体界面终止于 {111}/{110} 平面，并且这种行为对于与 Kurdjomov- 的有理界面更加明显。萨克斯取向关系。人们发现界面偏析不仅受界面晶体学的控制，而且还受溶质原子的键合特性的控制。溶质元素在非理性界面处表现出较高的界面过剩量。此外，观察到奥氏体-铁素体界面平面中选定溶质元素的不均匀分布。我们的研究结果强调了考虑五个独立的晶体学参数和相间边界的化学结构的重要性，事实上也是必要的，以对双相材料的机械和其他关键性能进行高级控制。