## 1 Introduction  
Maraging 18 Ni-300 steel is a type of low-carbon nickel-rich steel alloy that has become increasingly popular in the aerospace, defense, and medical industries due to its unique combination of strength, toughness, and corrosion resistance [1; 2; 3]. The term'maraging' is derived from a combination of the words \"martenasitic\" and \"aging\". The martensitic component of the term refers to the body-centered tetragonal crystal structure of the steel, while the aging component refers to the process by which the material is strengthened in the aging heat treatment. The chemical composition of maraging 18 Ni-300 steel includes approximately 18% nickel and 300 ppm carbon, along with trace amounts of other elements such as cobalt, molybdenum, and titanium. This specific composition gives the steel its unique properties, including a high strength-to-weight ratio, excellent toughness, and exceptional resistance to corrosion and wear. Laser powder bed fusion (LPBF) is a type of additive manufacturing technique that uses a high-powered laser to melt and fuse successive layers of metal powder to form a 3D object [4; 5]. In this process, powdered metallic feedstock material is distributed in a powder bed and then each layer is fused by the laser heat source. Three-dimensional metallic components are produced by the repetition of this layering process. This process is highly precise, allowing for the creation of complex geometries and intricate shapes that would be difficult or impossible to produce using traditional manufacturing methods. LPBF is particularly well-suited for the production of maraging 18 Ni-300 steel, as the unique combination of the low carbon content and the age-hardenability of the maraging steel allows for the creation of crack-free parts with fine, uniform microstructures that exhibit exceptional strength and durability [6; 7; 8; 9]. In this regard, the relatively low carbon content of the maraging 18 Ni-300 steel can effectively prevent the cold cracking caused by the rapid cooling-induced brittle martensite phase formation during LPBF, while the alloy can be easily hardened by the post solution and aging heat treatments. Conventionally, the heat treatment of the maraging 18 Ni-300 steel includes two stages consisting of a short solution treatment above 800 \({}^{\circ}\)C, followed by aging at around 500 \({}^{\circ}\)C for several hours [10; 11]. In the first stage, the solution treatment temperature is chosen to be higher than the austenite transformation temperature of this alloy to ensure the austenitic microstructure of the steel, and this allows the alloying elements to dissolve into the austenitic matrix. In the second stage of aging, the alloying elements precipitate out of solution and form nano-sized intermetallic compounds that strengthen the alloy. In the 18 Ni-300 steel, several intermetallic precipitates such as Ni\({}_{3}\)Ti, Ni\({}_{3}\)Mo, and Ni\({}_{3}\)(Mo,Ti) are known to precipitate during the aging treatment with sizes of 8-50 nm [6; 12; 13]. On the other hand, recent studies have demonstrated that the LPBF-processed maraging 18 Ni-300 steel can exhibit exceptional strength and toughness without the need for the solution treatment. Unlike traditional manufacturing methods, which often require solution treatment to dissolve the alloying elements, the microstructure of the maraging steel fabricated by LPBF has a fine structure with near fully dissolved alloying elements due to the sufficiently fast cooling rate of LPBF of up to 10\({}^{6}\)\({}^{\circ}\)C/s. This enables the steel to skip the solution heat treatment. For this reason, the maraging steel produced by LPBF can exhibit excellent tensile properties by only performing an aging heat treatment [9; 14; 15; 16]. When producing metallic components via LPBF, residual stress is a common challenge that can arise during the manufacturing process. Residual stress is an internal stress that remains within a material after it has been subjected to severe deformation or material processing.