In this work, C300 maraging steel powder feedstocks at different titanium contents (0.72 and 1.17 wt%) were additively manufactured using the laser powder bed fusion (LPBF) technique to systematically study the mechanical behavior of the material in both as-built and heat-treated conditions. X-ray diffraction techniques along with electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) were employed to investigate the microstructural characteristics and phase formation in the as-built and heat-treated samples. After heat-treating at 490 °C for 6 h, the HighTi maraging steel showed higher strength and ductility (2057.74 MPa and 4.05%). The microstructural characterization proved that this alloy contains a higher amount of reverted austenite (17.89 wt%), which resulted at higher strength as results of the transformation induced plasticity (TRIP) effect. In terms of ductility improvement, the fiber/copper texture developed in the HighTi sample provided a higher driving force to transform the reverted austenite to martensite. As the TEM analyses revealed, needle-shaped Ni₃Ti and spherical Ni₃Mo precipitates were found in both LowTi and HighTi alloys, where the HighTi one showed higher volume fraction of Ni₃Ti precipitates, and consequently, higher values of tensile strength, which can be explained, based on the Orowan mechanism.

在这项工作中，使用激光粉末床熔合（LPBF）技术对不同钛含量（0.72和1.17 wt％）的C300马氏体时效性钢粉原料进行了增材制造，从而系统地研究了材料在建态和热态下的力学行为。治疗条件。X射线衍射技术与电子背散射衍射（EBSD）和透射电子显微镜（TEM）一起用于研究已加工和热处理样品的微观结构特征和相形成。在490°C热处理6 h后，HighTi马氏体时效钢表现出更高的强度和延展性（2057.74 MPa和4.05％）。显微组织特征证明该合金含有较高含量的可逆奥氏体（17.89 wt％），由于转变诱导可塑性（TRIP）效应，其强度更高。在延展性改善方面，HighTi样品中形成的纤维/铜织构提供了更高的驱动力，可将还原的奥氏体转变为马氏体。TEM分析表明，针状镍在LowTi和HighTi合金中均发现₃ Ti和球形Ni ₃ Mo析出物，其中HighTi合金显示出更高的Ni ₃ Ti析出物体积分数，因此基于Orowan机理可以解释较高的拉伸强度值。 。