Advanced high-strength steels (AHSS) have been developed with the objective of minimizing fuel consumption and carbon footprints by reducing vehicle weights, and are currently the preferred choice within the automotive industry [1,2,3]. Among these steels, dual-phase steels have emerged as a significant area of interest. The high strength of the structural components of vehicles is associated with enhanced formability due to the low yield strength, which contributes to passenger safety. Dual-phase steels are among the most widely used in the AHSS family [4,5,6]. The microstructure of dual-phase steels is composed of martensite and ferrite phases, together creating an intricate interplay between strength and ductility. The production of dual-phase steels is achieved through the heating of the material to the α+γ regions, followed by a rapid cooling process that enables the transfer of the austenite phase to the martensite phase. During the martensitic transformation, a diffusionless phase change occurs, whereby the face-centered cubic (FCC) structure of austenite shifts to a body-centered tetragonal (BCT) martensite structure. The aforementioned transformation gives rise to internal stresses as a consequence of the dissimilar lattice structures, which in turn result in an enhanced dislocation density and increased hardness in the martensite phase [7,8,9]. The martensite phase is rich in carbon, thereby providing the strength of steel. In contrast, the ferrite phase gives steel ductility [10]. The volume fraction and structures of the phases present in the steel content may vary depending on the heat treatment and cooling process, which in turn determines the characteristics of the steel [11]. The distribution of martensite particles within the ferrite phase, the size and morphology of the phases, and the mechanical properties of the material are all influenced by one another [12,13].

Finite element analysis tools have revolutionized the modeling of steel microstructures, providing an avenue to study mechanical properties without physical production. The microstructure of steel can be modeled with finite element analysis software developed in recent years. The mechanical properties and deformation behavior of steel can be determined according to the particle size, grain structure, and phase volume fraction, without the necessity of steel production. In accordance with the material properties, the microstructures that are generated within the computer environment can be analyzed through the use of the representative volume element (RVE) method. In the literature, Arezodar and Nikbakht conducted a deformation analysis on dual-phase steels with varying martensite volume fractions and particle sizes. It was observed that an increase in the martensite volume fraction and a decrease in particle size resulted in enhanced mechanical properties [12]. However, their work primarily focused on volume fraction and did not examine the specific role of martensite particle size across different sizes, which is a key aspect of this study. Anbarlooie et al. conducted an analysis of dual-phase microstructures with different martensite volume fractions, employing 2D and 3D representative volume elements [14]. Their research demonstrated the usefulness of the RVE method, but the specific effects of particle size on stress–strain behavior were not fully explored. Eghtesad and Knezevic [15] employed the 3D representative volume element method to examine the microstructures of DP590, DP980, and DP1180 dual-phase steels. Their focus was mainly on volume fraction, leaving particle size effects less explored. Hosseini-Toudeshky et al. performed an analysis of the effects of martensite volume fraction using real 2D dual-phase microstructure geometries [16]. Mangas et al. investigated the uniaxial tensile behavior of dual-phase steels with 2D representative volume elements at varying martensite volume fractions [17]. Rana and colleagues studied the cyclic plastic deformation of dual-phase steels with varying martensite volume fractions using 2D representative volume elements [18]. These 2D studies provided insights into general deformation mechanisms but lacked a detailed 3D analysis of particle size effects, which is critical for understanding microstructural behavior. The findings of these studies indicated that the level of stress experienced by the material increased in direct correlation with the martensite volume fraction. In their study, Li et al. demonstrated that an increase in carbon content results in enhanced strength, while damage occurs during deformation in the ferrite phase [19]. Matsuno et al. investigated the effect of martensite particle type by employing 3D representative volume elements and determined that the banding-type structure markedly enhanced tensile strength [20]. Basantia et al. examined the influence of representative volume element size on the prediction of tensile strength in dual-phase steel. It was demonstrated that the accuracy rate increased in conjunction with an increase in the representative volume element size [21]. While Matsuno et al. [20] and Basantia et al. [21] highlighted the importance of martensite morphology and RVE size, they left a gap in understanding the effects of varying particle sizes within a 3D context. In a study conducted by Amirmaleki et al., DP500 and DP600 dual-phase steels were analyzed using the 3D RVE method, and the results were found to be in close agreement with the experimental findings [22]. Abid et al. demonstrated that reducing the size of martensite particles has the effect of increasing tensile strength. While their study focused on a martensite particle size and lacked a detailed examination of the stress–strain relationship in 3D [23].