Transformation-induced Plasticity Research Articles

Achieving unexpected strength and ductility synergies in heterogeneous metastable lamellar steels

High-strength steel with excellent ductility is pivotal for the formability and safety of critical structural components. Here, a heterogeneous metastable lamellar steel, composed of alternating lamellar ferrite and austenite aligned with the rolling direction, was developed through an innovative combination of warm rolling and immediate annealing processes. This novel design overcomes the strength-ductility trade-off, achieving high ultimate tensile strength (∼1.2 GPa) and excellent uniform elongation (∼78%), pushing the product of ultimate tensile strength and uniform elongation to an ultra-high level (> 90 GPa %). The high tensile strength is attributed to ultrafine lamellar grains and significant work hardening induced by the hetero-deformation and transformation-induced plasticity (TRIP) effect. The exceptional ductility is a result of the synergy of multiple plasticity mechanisms, including (i) the inherent plastic deformation ability of lamellar microstructure and the hetero-deformation-induced hardening in the early deformation period, (ii) the persistent TRIP effect induced by the lamellar austenite with high mechanical stability and the elimination of strain localization caused by prolonged strain hardening due to the coordinated deformation of lamellar austenite and ferrite in the middle deformation period, and (iii) delamination cracking in the late deformation period. This approach adopted in current work offers a straightforward and economically feasible pathway for fabricating advanced high-strength steel with superior performance.

Deformation-induced martensitic transformation kinetics in TRIP-assisted steels and high-entropy alloys

In this study, the sigmoidal kinetics of deformation-induced martensitic transformation (DIMT) in the transformation-induced plasticity (TRIP)-assisted alloys, including metastable high-entropy alloys (HEAs), austenitic stainless steels, and advanced high-strength steels (AHSSs) such as low-alloyed TRIP steels, medium-Mn steels, and quenching and partitioning steels, were studied using various models. To tune mechanical stability, the influences of stacking fault energy (SFE), chemical composition, austenite grain size, deformation temperature, strain rate, and stress state were considered. The novel Fe47Co30Cr10Ni5V8-xSix (x = 3, 4, and 6 at.%) alloys were the main investigated HEAs in the present work, in which silicon addition effectively led to lowering SFE and faster DIMT kinetics by promoting the formation of body-centered cubic α΄-martensite. The Olson-Cohen, Guimaraes (based on Johnson-Mehl-Avrami-Kolmogorov analysis), Shin, and Ahmedabadi models were analyzed and critically discussed. Moreover, a Hill-based sigmoid model was formulated as fα' / fsat = 1 – p / (p + εq) with the parameters p and q characterizing the stability of austenite, and fsat representing the saturated volume fraction of α΄-martensite. It was demonstrated that χ = p × q can be considered the sole austenite stability parameter. It was concluded that the proposed Hill-based model, demonstrating the highest accuracy among the studied models, can effectively simulate the kinetics of α΄-martensite formation.

Effect of deep cryogenic treatment on microstructure and mechanical properties of Fe50Mn30Co10Cr10 high entropy alloy fabricated by laser metal deposition

As a typical additive manufacturing technology, laser metal deposition (LMD) has been widely used to process high entropy alloy (HEA). However, deposited products usually have poor mechanical properties. In this study, deep cryogenic treatment (DCT) is proposed to enhance the mechanical performance of the laser melting deposited Fe50Mn30Co10Cr10 high entropy alloy. The tensile strength, hardness and strength-plasticity product of the HEA after 48 h of immersion by DCT processing were 901 MPa, 286HV and 33.3 GPa%, respectively. Compared with the as-deposited state, the HCP ε phase content and tensile strength of the deep cryogenic treated (DCTed) sample increased by 2.2 times and 30.8 %, respectively, while the average grain size decreased by 58.0 %. Furthermore, the friction coefficient and wear rate of the DCTed samples reduced by 25.6 % and 30.3 %, respectively. The high temperature gradient soaking in liquid nitrogen induced dynamic recrystallization, refining the FCC γ grain structures in the HEA. Meanwhile, the samples contained more HCP ε phase due to the transformation-induced plasticity (TRIP) effect triggered by thermal stress. The results indicate that the effects of fine-grain strengthening and second-phase particle dispersion strengthening contribute to the excellent mechanical performance. DCT processing provides a simple and effective way for overcoming the strength-ductility trade-off in the additive manufactured Fe50Mn30Co10Cr10 HEA.

Stability of retained austenite and its effect on tensile properties and hole expansion performance of high-strength steel

Medium manganese steel has a ferritic matrix with retained austenite as the secondary phase at room temperature (RT). The effect of the transformation-induced plasticity (TRIP) of retained austenite on steel has earlier been found to result in an excellent combination of high strength and ductility, making it a promising candidate as a third-generation advanced high-strength steel (AHSS) for automotive applications. Therefore, extensive research has recently been conducted with the aim to increase the amount of retained austenite in steel, thereby enhancing the strength and ductility of the steel. However, an increase in the amount of retained austenite can be detrimental to the HER, which is due to its low mechanical stability and the transformation to martensite when forming holes by punching. However, there has been relatively little research on this topic.The impact of the mechanical stability of retained austenite on the tensile properties and hole expansion ratio (HER) of high-strength medium-Mn steel have been investigated in the present study. Samples were prepared using one-step austenite-reverted-transformation (ART) annealing, which resulted in steel with 24.7 % retained austenite and moderate mechanical stability. The steel showed also an excellent combination of strength and ductility. Samples were also prepared using two-step annealing, which showed a positive effect on the HER of the steel, regardless of the processing method used for the formation of a central hole on the samples. However, it slightly reduced the ductility of the steel. For all these samples, the impact of the retained austenite on the HER was found to be closely related to its mechanical stability and content in the steel.Retained austenite with poor stability transformed into hard martensite during the punching processing of holes. In contrast, the retained austenite with a relatively high stability showed a positive effect during the whole hole expansion deformation process. It decreased the stress concentration and, thereby, improved the HER. Thus, the present study has found that it is of the greatest importance to improve the stability of the retained austenite in high-strength medium-Mn steel, and to suppress its transformation to martensite during the punching of holes in the steel.

Enhancing mechanical properties of medium Mn steel by warm rolling based on laminated elemental segregation

The hot-rolled microstructure of medium Mn steel has coarse grains and severe elemental segregation, resulting in low strength and plasticity. Constructing a multiphase structure, refining the microstructure, and regulating elemental segregation enhance the mechanical properties. In this study, liquid nitrogen treatment created a layered distribution of austenite and martensite. Warm rolling was then used to reduce layer thickness and refine grain structure. After liquid nitrogen and warm rolling treatments, the strength and plasticity of medium Mn steel increased to 1270 MPa and 23.3%, respectively, far exceeding the hot-rolled state (724 MPa, 12.8%). Warm rolling also triggers austenite reverted transformation (ART) and introduces high-density dislocations, further improving austenite stability. This strengthening effect is higher than that from intercritical annealing alone. Improved austenite stability delays the transformation induced plasticity (TRIP) effect, preventing brittle fracture and enhancing deformation coordination between layers, significantly increasing the plastic deformation capacity of medium Mn steel.

New strategy to simultaneously improve strength-toughness balance for low-carbon ultrastrong steel by multi-step heat treatment process

The quenching-partitioning-tempering (QPT) multi-step heat treatment process was employed to enhance the strength-toughness balance of low-carbon ultrastrong steel based on the controllable transformation-induced plasticity (TRIP) effect and co-precipitation strengthening. The aging embrittlement of ultrastrong steel, with an impact toughness of only 5.8 J at peak strength, has been effectively addressed through the QPT process. The sufficient reversed austenite (RA) can be obtained by controlling the partition temperature to 650 °C, followed by aging at 550 °C to fully re-precipitate nanoparticles. The volume fraction of RA in QPT650 steel reached 16.4 %, and the number density of nanoparticles increased dramatically, resulting in a high yield strength of 1233 MPa and excellent impact toughness of 60.4 J. The coarsening and re-precipitation of nanoparticles were clarified, and the strengthening increments of QPT650 steel reaches 584.6 MPa, and the substantial enhancement of Orowan strengthening is responsible for the high yield strength. The excellent impact toughness of QPT650 steel is attributed to the obvious TRIP effect of RA that consumes a large amount of crack propagation energy, and a small number of sheared nanoparticles provide limited micro-cracks, resulting in a strong crack resistance.

Effect of Co-content on microstructure, phases, and mechanical properties of laser additive manufactured Cox(CrNi)100-x alloy

This study describes the combination of mechanical properties of the CoCrNi medium entropy alloy system by tailoring its non-equiatomic compositions. The Laser Directed Energy Deposition (LDED) based Additive Manufacturing (AM) technique is deployed to fabricate the Cox(CrNi)100-x (x=40, 50, 60) alloy system. All compositions exhibit the formation of solidification substructures, with the refinement of subgrain size correlated with an increase in Co-content. The Co40 alloy exhibited a single-phase FCC structure, while Co50 (3.1 % ε-martensite) and Co60 (53.6 % ε-martensite) exhibited dual FCC+HCP structure during deposition. The combined effect of dislocation slip, deformation twinning, and deformation-induced HCP ε-martensite transformation strengthened the Co40 alloy during deformation. However, the Transformation-Induced Plasticity effect (TRIP) resulted in greater HCP ε-martensite transformation during deformation. Due to limited slip systems in the HCP structure, the Co60 alloy showed lower strength. The TRIP effect is highly dominant in Co60 alloy due to the prevalent HCP phase fraction in the initial samples. This led to stress concentration at FCC grain boundaries and ε-martensite, resulting in early failure of the alloy. With the increase in Co-content, the deformation mechanism changed from dislocation slip to deformation twinning to HCP ε-martensitic transformation. The LDED-built Cox(CrNi)100-x alloy system showed a good combination of strength and ductility. The study suggests that additive manufacturing is an easier and more suitable technique for obtaining compositions with the desired combination of mechanical properties.

Ternary Mg-Sc-based TRIP alloys: Design strategy based on Sc-equivalent

This study addresses the transformation-induced plasticity (TRIP) effect observed in bcc single-phase Mg–Sc alloys, aiming to circumvent the strength-ductility tradeoff inherent in traditional Mg-based alloys. Introducing a third element (X = Zn, Y, Nd, Gd) significantly enhanced the strength of the binary Mg–Sc TRIP alloys, simultaneously preserving ductility due to the TRIP effect. Consequently, a ternary Mg–Sc–X TRIP alloy with a bcc single-phase, for instance, achieved an ultimate tensile strength of approximately 380 MPa and a fracture elongation of around 41%, surpassing the conventional tradeoff. Furthermore, we introduce the design strategy of Sc-equivalent (Sceq) to articulate the combined influence of Sc and X elements on the stability of the bcc phase. This novel approach demonstrates the room-temperature deformation behavior of the Mg–Sc–X ternary alloy can be predicted and modulated, showcasing superelasticity (17.5 < Sceq < 19.5) and TRIP effect (19.0 < Sceq < 21.0).

Bidirectional Phase Transformations in Multi-Principal Element Alloys: Mechanisms, Physics, and Mechanical Property Implications.

The emergence of multi-principal element alloys (MPEAs) heralds a transformative shift in the design of high-performance alloys. Their ingrained chemical complexities endow them with exceptional mechanical and functional properties, along with unparalleled microscopic plastic mechanisms, sparking widespread research interest within and beyond the metallurgy community. In this overview, a unique yet prevalent mechanistic process in the renowned FeMnCoCrNi-based MPEAs is focused on: the dynamic bidirectional phase transformation involving the forward transformation from a face-centered-cubic (FCC) matrix into a hexagonal-close-packed (HCP) phase and the reverse HCP-to-FCC transformation. The light is shed on the fundamental physical mechanisms and atomistic pathways of this intriguing dual-phase transformation. The paramount material parameter of intrinsic negative stacking fault energy in MPEAs and the crucial external factors c, furnishing thermodynamic, and kinetic impetus to trigger bidirectional transformation-induced plasticity (B-TRIP) mechanisms， are thorougly devled into. Furthermore, the profound significance of the distinct B-TRIP behavior in shaping mechanical properties and creating specialized microstructures c to harness superior material characteristics is underscored. Additionally, critical insights are offered into key challenges and future striving directions for comprehensively advancing the B-TRIP mechanism and the mechanistic design of next-generation high-performing MPEAs.

Influence of crystallographic textures on the hydrogen embrittlement resistance of austenitic stainless steel

Hydrogen embrittlement (HE) resistance is a significant concern in austenitic stainless steel (ASS) used for hydrogen transportation and storage. While microstructure-controlled methods to enhance HE resistance have been extensively studied in ferritic steels, comprehensive research on microstructure effects in ASS is lacking. In this study, two 316L ASSs with different microstructures were evaluated for HE resistance using electrochemical hydrogen charging. The steel with abundant in <111>+<110> orientations showed a significant elongation reduction after hydrogen charging. It revealed that, from the hydrogen permeation and thermal desorption analysis (TDA) results, effective diffusivity and activation energy of hydrogen were changed along the crystallographic orientation distributions. Also, transformation induced plasticity (TRIP) and twinning induced plasticity (TWIP) behavior affecting to the HE resistance preferentially formed in grains with <111> and <110> orientations rather than in those with <001> orientation during plastic deformation. Therefore, the study suggests that reinforcing the <001> microstructure is advantageous for improving HE resistance in 316L ASS.

Comparative study of tensile properties and impact toughness of duplex lightweight steel

Herein, a comparative study regarding the tensile properties and impact toughness of duplex lightweight steel and its deformation behavior was conducted to broaden its application from automotive steel sheets to thick-plate applications at various temperatures using Fe-0.2C–15Mn–6Al and Fe-0.4C–15Mn–6Al hot-rolled steels as model alloys. These steels revealed duplex microstructures with a large fraction of γ austenite (>0.7), featuring elongated δ ferrite grains aligned with the rolling direction and nearly globular γ grains. Both steels demonstrated an exceptional balance of tensile strength and ductility despite their low temperatures ranging from −20 °C to −100 °C, which was attributed to the active dynamic strengthening mechanisms, such as transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP). However, contrary to the promising tensile test results, the steels demonstrated low values of the impact absorbed energy at temperatures ranging from −60 °C to −196 °C. This difference was likely owing to the rapid deformation rates in the Charpy impact tests compared to tensile tests, leading to the evolution of significant damage indicated by deep parallel cracks within the δ grains, without significantly activating the TRIP effect. Therefore, despite the impressive low-temperature tensile properties of the duplex lightweight steel, its suitability for cryogenic thick-plate applications must be approached with caution owing to the potential for compromised mechanical properties under sudden impact conditions.

FCC twins and martensites responses of metastable dual-phase high entropy alloy to friction stir processing

Fe50Mn30Co10Cr10 dual-phase high entropy alloy (DP-HEA) has good application prospects in the nuclear and automotive industries due to its strength-ductility synergistic effect. The initial volume fractions of FCC twins and HCP martensites in Fe50Mn30Co10Cr10 HEA affect the relative contribution of transformation-induced plasticity and twinning-induced plasticity to the alloy's strength and ductility under loading conditions. Understanding the relationship between FCC twins and martensites is crucial during the friction stir process (FSP). In this study, the microstructure of Fe50Mn30Co10Cr10 HEA as FSP condition was studied. The HCP phase in the base metal almost completely transformed into the FCC phase during FSP. Both FCC twin and HCP martensite transformations serve to alleviate strain in the FCC matrix. The initiation of FCC twin and martensite formation depends on critical stress levels at different temperatures. Higher strain and coarser grains promote more martensite formation, while finer grains and lower strain impede it, causing FCC twins to occur before HCP martensites during the cooling process of materials in the processed zone. These findings offer insights into controlling the volume fractions of twins and martensites in FSPed DP-HEA, thereby potentially enhancing the mechanical properties of DP-HEA.

Effect of Cu upon recrystallization and mechanical properties of TRIP-assisted high entropy alloy

The face-centered cubic (FCC) high-entropy alloys (HEAs) have been hindered in their engineering applications due to their low yield strength. Combining multiple strengthening mechanisms with phase transformation-induced plasticity (TRIP) may serve as an effective approach to overcome the strength-ductility trade-off. In this study, (Co3Cr1.6FeNi)100-xCux (x = 0,2) high entropy alloys (HEAs) were designed. A straightforward processing route, involving hot rolling followed by annealing, was utilized to produce single-phase FCC HEAs. The alloy doped with 2 at.% Cu achieved a perfect combination of strength and ductility. It was also found that the addition of Cu suppresses the recrystallization process during the hot rolling and annealing of the alloy. The increase in strength is attributed to the synergistic effects of various strengthening mechanisms dominated by dislocation strengthening and heterogeneous deformation induced strengthening, while the TRIP effect ensures continuous strain hardening capability of the alloy while maintaining high yield strength and ensuring good ductility. These results offer valuable insights into the design and development of high-performance HEAs with exceptional strength and ductility.

Effect of thermo-mechanical treatment on cryogenic mechanical properties of a medium-entropy Fe65Co12.5Ni12.5Cr9.5C0.5 alloy produced by the laser-based powder bed fusion

Microstructure and mechanical properties of the Fe65Co12.5Ni12.5Cr9.5C0.5 (in at.%) medium-entropy alloy obtained by the laser-based powder bed fusion (PBF-LB) was investigated in the as-produced condition and after (i) annealing in the interval 800–1100 °C or (ii) cold rolling followed by annealing at 800 °C. The as-produced microstructure was found to be surprisingly stable; noticeable recrystallization occurred only after annealing at 1100 °C. Cold rolling resulted in the formation of typical deformed microstructure, while further annealing led to the formation of a fine-grained recrystallized microstructure. A considerable improvement in cryogenic mechanical properties was obtained after some thermo-mechanical treatments due to the transformation-induced plasticity (TRIP) effect. The cold-rolled alloy had the best cryogenic strength characteristics; yield strength and ultimate tensile strength were found to be 1740 MPa and 2235 MPa, respectively. High strength was combined with a pronounced value of elongation to fracture of 24 %. Detailed analysis of microstructure and corresponding mechanical behavior changes caused by various processing of the as-produced alloy are presented.

Role of cementite on tensile properties in auto-tempered 0.15C–5Mn martensitic steel

The effects of austenitizing temperature and cooling rate on microstructure and subsequent tensile properties were investigated in 0.15C–5Mn martensitic steels. Tensile strength and elongation increased with decreasing austenitizing temperature (1000 °C to 800 °C) in both air-cooled and water-quenched steels. Improvement of tensile properties originated from the promoted transformation-induced plasticity (TRIP) effect, as lower austenitizing temperature limited Mn diffusion to make cementite preferred site for Mn partitioning, thereby increasing the fraction of retained austenite after heat treatment. Cooling rate also affected the mechanical properties, as air-cooled samples showed lower strength and higher elongation compared to water-quenched samples. During the air-cooling, supersaturated carbon in martensite is redistributed to form additional carbides by auto-tempering effect. The formation of carbides softened the martensite to decrease strength while increased tensile elongation. Fraction of retained austenite influenced by the austenitizing temperature and formation of carbide affected by the cooling rate acted as competing mechanisms affecting the tensile properties of the martensitic steels, indicating that heat treatment should be controlled carefully to obtain the desirable mechanical properties.

In-situ Laue micro-diffraction during compression tests on Ce-TZP single crystal micropillars

The widespread use of ceramics faces challenges due to their limited ductility, stemming from a lack of dislocation-induced plasticity. This study focuses on ceria-stabilized tetragonal zirconia a ceramic that benefits from its unique tetragonal-to-monoclinic phase transformation under stress, leading to transformation-induced plasticity (TRIP). Employing a micro-scale in-situ approach, the study aims to understand the mechanisms governing TRIP, particularly focusing on crystallographic features of the transformation. In-situ compression tests using synchrotron light source and Laue micro-diffraction were conducted on single crystal micropillars with various orientations. Results show that crystal orientation significantly affects the mechanical behaviour, with transformation being most likely when the resolved shear stress on {100} planes of the double-cell and along the <010> direction is highest. The martensite theory validates the correspondences obtained experimentally. This research provides insights into enhancing the mechanical properties of ceramics by leveraging the TRIP mechanisms.

The design of appropriate Si content overcomes the strength-ductility trade-off in dual-phase high entropy alloy

To reduce the stacking fault energy (SFE) of the alloys, silicon (Si) was introduced into Fe40Mn35Co20Cr5 dual-phase high entropy alloys (HEAs). We propose a novel mechanism supported by first-principles calculations that predicts Si atoms may preferentially substitute Cr atoms, resulting in enhanced lattice distortion and reduced SFE. Experimental results indicate that incorporating 0.2 wt % Si enhances the ductility of the alloy while maintaining its strength through a synergistic effect involving dislocations and phase transformation. Furthermore, in the Si0.2 alloy, the integrity of 9 R structures were preserved, thereby enhancing the transformation-induced plasticity (TRIP) effect and facilitating attainment of an optimal balance between strength and ductility. However, incorporation of 0.1 wt % and 0.3 wt % Si content leads to a decline in ultimate tensile strength due to improper Si content causing grain growth and premature phase transition. Therefore, meticulous selection of an appropriate Si content is crucial for simultaneously enhancing both strength and ductility.

Achieving high ductility in Fe45Mn35Co10Cr10 metastable high entropy alloy by constructing chemical boundary with stacking fault energy heterogeneity

Additively-manufactured metastable high entropy alloys are emerging as promising alternatives for energy absorption in protective equipment due to their exceptional ductility. In this study, an elongation of over 50 % was achieved in a directed energy deposition fabricated Fe45Mn35Co10Cr10 metastable high entropy alloys (MHEAs). The inherent high cooling rate and repeated heat treatment in the directed energy deposition process were harnessed to deliberately induce an uneven distribution of Mn elements, forming a cellular structure with chemical boundary. The unique heterogeneity stacking fault energy results in a synergistic interplay of multiple deformation mechanisms such as, dislocation slip, transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP). In the initial stage of deformation, dislocation slip and TRIP contribute to the main plasticity. Stacking faults/martensite are confined within the cellular structure with low stacking fault energy (SFE). As strain increases, TWIP and TRIP are activated in the high SFE regions. Twins and martensite across the cell wall were observed. As strains exceed 40 %, primary martensite variant and twinning with a particular intersection angle take place to further enhance the deformation ability. The chemical boundary with stacking fault energy heterogeneity not only simultaneously activates both TRIP and TWIP, but also maintains the martensite and twins at the nanoscale.

Understanding plasticity in multiphase quenching & partitioning steels: Insights from crystal plasticity with stress state-dependent martensitic transformation

This study develops a novel crystal plasticity (CP) model incorporating deformation-induced martensitic transformation (DIMT) and transformation-induced plasticity (TRIP) effect to predict the complex interplay between microstructural evolution and mechanical behavior in a third-generation advanced high-strength steel QP980. This model introduces phenomenological theory of martensite crystallography (PTMC) based TRIP theory and DIMT kinetics grounded on nucleation-controlled phenomenon. Notably, the DIMT model is improved by utilizing a geometric approach for calculating shear band intersections. A virtual multiphase representative volume element (RVE) based on the Voronoi tessellation is generated for the QP980 steel, which comprises ferrite, martensite, and retained austenite (RA). The study highlights how phase transformation affects mechanical properties, notably the strengthening from transformed martensite and the mechanical alterations in RA due to the TRIP effect. The DIMT kinetics dependent on stress states such as uniaxial tension (UT), uniaxial compression (UC), plane strain tension (PST), and equi-biaxial tension (EBT) are analyzed using the developed model. The role of microstructural surroundings on martensitic transformation is also examined. Furthermore, analysis under biaxial loading angles using the model reveals an asymmetric yield surface, with more pronounced changes in yield stress in the tensile region due to accelerated transformation behaviors, as opposed to the more gradual transformations in the compressive region. This study provides valuable insights into the deformation mechanisms of the third-generation advanced high-strength steels including relationship between plastic anisotropy, transformation kinetics, and microstructural evolution.

Interpass temperature strategies for compressive residual stresses in cladding low-transformation-temperature material 16Cr8Ni via wire arc additive manufacturing

Low-transformation-temperature (LTT) materials induce compressive residual stresses within an effective depth in wire arc additive manufacturing (WAAM), which is well suited for cladding applications. However, this role was found to be sensitive to the phase transformation sequence. We developed an LTT material—16Cr8Ni (16Cr8Ni-LTT)—and to explore its potential, it was clad onto a KA36 substrate via WAAM. Three different interpass temperature strategies were designed as follows: (1) no interpass temperature control; (2) interpass temperature controlled at approximately 270 °C above the martensite transformation start temperature (Ms = 200 °C) for simultaneous phase transformation; and (3) interpass temperature controlled at approximately 50 °C below the martensite transformation finish temperature (Mf = 60 °C) for sequential phase transformation. A thermal elastic-plastic numerical model considering the phase transformation-induced plasticity (TRIP) was developed using in-house software, JWRAIN-Hybrid, to reproduce the temperature field and residual stresses of 16Cr8Ni-LTT cladding. X-ray diffraction (XRD) and contour methods were employed for residual stress measurements. The high accuracy of the model was validated in terms of the temperature, deformation, and residual stress. The reproduced maximum historical temperature distributions were combined with hardness tests to identify the depths and temperatures of the heat-affected zone (HAZ). The measured maximum compressive residual stresses induced by the three interpass temperature strategies for cladding 16Cr8Ni-LTT were −503, −420, and −720 MPa. Moreover, irrespective of the adopted interpass temperature strategy, both longitudinal and transverse residual stresses were compressive in the 16Cr8Ni-LTT cladding. This study provides scientific insights into LLT-induced compressive residual stresses and highlights the superiority and flexibility of cladding LTT materials via WAAM for improving the resistance of large metal components to fatigue and corrosion.