Prediction of the microstructure evolution and hot cracking index in electron beam welding of Inconel 713LC gas turbine blades

西门子加拿大公司是世界上电气工程、能源和能源领域最大的公司之一 运输公司专门生产用于发电的燃气轮机发动机。在这样的应用中 在温度较高的情况下，材料的选择是获得高效率和可靠性的关键。对于这样的 用途：镍基高温合金因其良好的蠕变抗力、抗拉强度和氧化性能而被广泛使用。 抵抗。西门子特别选择了Inconel 713LC合金来制造符合以下条件的涡轮叶片 在高温下承受拉伸载荷。在加入过程中出现了需要解决的产业问题 通过电子束焊接(EBW)将涡轮叶片安装在护罩位置。相关联的较低热输入 采用这种焊接工艺，熔合区(FZ)和热影响区(HAZ)较小，冷却程度较高 费率。由于FZ的快速凝固，组织变得比母体的更细小 导致局部蠕变抗力降低的材料。除此之外，产生的高拉应力 在冷却过程中，增加了FZ和HAZ的热裂风险。视焊接操作情况而定 在这种情况下，高废品率成为该公司的一个重要问题。在过去几年里， 西门子加拿大公司的工程师已经在电子束焊接的热机械建模方面进行了大量的工作 进程。他们可以模拟焊缝周围材料中的热流，以便获得一张地图 已知会增加热裂风险的温度分布和残余应力。该计划的目的是 建议的研究项目是评估预测钢的微观结构演变的可行性。 Inconel 713LC合金在FZ和HAZ中，以确定可用于 评估冷却过程中裂纹形成的风险，以及这种现象更容易出现的位置 发生。该项目的独创性与这种工艺-组织-性能关系有关，而不是 通常存在于用于焊接过程的商业有限元软件工具中。

Siemens Canada, one of the largest companies in the world in the field of electrical engineering, energy and transportation is specialised in gas turbine engines used for power generation. In such applications at high temperature, the selection of materials is critical in order to obtain high efficiency and reliability. For such applications, nickel-based superalloys are used due to their good creep resistance, tensile strength and oxidation resistance. Siemens selected specifically the Inconel 713LC alloy for the fabrication of turbine blades that are subjected to tensile loading at high temperature. The industrial problem to be solved appears during the joining of turbine blades in the shrouds location by electron beam welding (EBW). The lower heat input associated with this welding process leads to smaller fusion zone (FZ) and heat-affected zone (HAZ) and high cooling rates. As a consequence of fast solidification of the FZ, the microstructure becomes finer than that of the parent material resulting in localised reduced creep resistance. In addition to that, the high tensile stresses generated during cooling increase the risk of hot cracking in the FZ and HAZ. Depending on the welding operational conditions, the high level of rejected parts becomes an important issue for the company. During the last years, the engineers of Siemens Canada have deployed a major effort in the thermomechanical modeling of the EBW process. They could simulate the heat flow in the materials around the weld in order to obtain a map of temperature distribution and residual stresses that are known to increase the risk of hot cracking. The aim of the proposed research project is to evaluate the feasibility to predict the evolution of the microstructure of the Inconel 713LC alloy in the FZ and in the HAZ in order to determine a hot cracking index that could be used to evaluate the risk of crack formation during cooling and the locations where this phenomenon is more prone to occur. The originality of the project is related to this process-microstructure-properties relationship that is not normally present in commercial finite element software tools for welding processes.