Cast irons are a class of iron-carbon alloys that are extensively utilized owing to their cost-effectiveness, excellent machinability, and high damping capacity. Nodular cast irons, also known as ductile irons and spheroidal graphite cast irons exhibit superior tenacity, ductility, and mechanical strength, thereby making them suitable for more demanding applications, particularly in the automotive industry and wind power generation. However, welding cast iron is a more complex, difficult, and meticulous process than welding steel mainly due to the high carbon content present in the alloy. Nevertheless, welding of these alloys is important and has various industrial applications. Gas tungsten arc welding has been employed but is not a common alternative. However, the high control over the energy transferred, simplicity of mechanization and presence of an inert protective atmosphere are interesting factors when considering the effect of the welding thermal cycle on the heat-affected zone (HAZ). Thus, this study aims to investigate the effect of the preheating temperature and post-weld heat treatment (PWHT) of nodular cast iron blocks partially remelted by the tungsten inert gas welding process on the microstructure and mechanical behavior of the HAZ. Notably, the use of higher preheating temperatures promotes improvements in the microstructure and, consequently, in the hardness of the HAZ. However, the optimum condition was achieved in the sample preheated at 350 °C and subjected to PWHT.

铸铁是一类铁碳合金，由于其成本效益、优良的机械加工性和高阻尼能力而被广泛使用。球墨铸铁，也称为球墨铸铁和球墨铸铁，具有优异的韧性、延展性和机械强度，因此适用于要求更高的应用，尤其是汽车工业和风力发电。然而，焊接铸铁是一个比焊接钢更复杂、更困难和更精细的过程，主要是因为合金中存在高碳含量。然而，这些合金的焊接很重要并且具有多种工业应用。已采用气体钨极电弧焊，但不是常用的替代方法。然而，对能量转移的高度控制，在考虑焊接热循环对热影响区 (HAZ) 的影响时，机械化的简单性和惰性保护气氛的存在是有趣的因素。因此，本研究旨在研究预热温度和焊后热处理 (PWHT) 对通过钨极惰性气体焊接工艺部分重熔的球墨铸铁块对热影响区组织和力学行为的影响。值得注意的是，使用更高的预热温度促进了微观结构的改进，从而提高了 HAZ 的硬度。然而，在 350 °C 预热并进行 PWHT 的样品中实现了最佳条件。本研究旨在研究通过钨极惰性气体保护焊工艺部分重熔的球墨铸铁块的预热温度和焊后热处理 (PWHT) 对热影响区组织和力学行为的影响。值得注意的是，使用更高的预热温度促进了微观结构的改进，从而提高了 HAZ 的硬度。然而，在 350 °C 预热并进行 PWHT 的样品中实现了最佳条件。本研究旨在研究通过钨极惰性气体保护焊工艺部分重熔的球墨铸铁块的预热温度和焊后热处理 (PWHT) 对热影响区组织和力学行为的影响。值得注意的是，使用更高的预热温度促进了微观结构的改进，从而提高了 HAZ 的硬度。然而，在 350 °C 预热并进行 PWHT 的样品中实现了最佳条件。HAZ 的硬度。然而，在 350 °C 预热并进行 PWHT 的样品中实现了最佳条件。HAZ 的硬度。然而，在 350 °C 预热并进行 PWHT 的样品中实现了最佳条件。