Effects of Substrate Preheating Temperatures on the Microstructure, Properties, and Residual Stress of 12CrNi2 Prepared by Laser Cladding Deposition Technique

Abstract

The 12CrNi2 alloy steel powder studied in the present paper is mainly used to manufacture camshafts for nuclear power emergency diesel engines. Laser cladding deposition is of great significance for the manufacture of nuclear power emergency diesel camshafts, which has the advantages of reducing material cost and shortening the manufacturing cycle. However, due to the extremely uneven heating of the components during the deposition process, a complex residual stress field occurs, resulting in crack defects and residual deformation of the components. In the present paper, 12CrNi2 bulk specimens were prepared on the Q460E high-strength structural steel substrate at different preheating temperatures by laser cladding deposition technique, and a finite element residual stress analysis model was established to investigate the effects of different preheating temperatures on the microstructure, properties, and residual stress of the specimens. The results of the experiments and finite element simulations show that with the increase of preheating temperature, the content of martensite/bainite in the deposited layer decreases, and the ferrite content increases. The proper preheating temperature (150 °C) has good mechanical properties. The residual stress on the surface of each specimen decreases with the increase of the preheating temperature. The longitudinal stress is greater at the rear-end deposition part, and the lateral residual stress is greater on both sides along the scanning direction.

Study on the Deformation Control and Microstructures of Thin-Walled Parts Repaired by Laser Cladding

“…Therefore, determining how to reduce the deformation of thin-walled parts during laser cladding repair has become the focus of a body of research. The formation reason and action rules of stress and deformation in laser cladding are very complex, and many experts and scholars have conducted many related investigations on this topic [16][17][18][19][20][21][22]. Wang et al [23] used different types of lasers to study the properties of formed AISI316L stainless steel thin-walled parts, and found that the ultimate tensile strength of the sample produced by a pulse laser was higher than that of the sample produced by a continuous-wave laser.…”

Process optimization of high entropy alloys by laser additive manufacturing

“…108 On the other hand, there were variations with sharp changes in the microhardness values of AlTiCrFeCoNi HEA at stage one of the experiments, which could be attributed to the small hardening effect in the heat-affected zones and the inner microstructure undergoing intricate phenomena before preheating under reoccurring thermal cycling resulting in the fluctuation in hardness values. 109 Consequently, the AlTiCrFeCoNi alloy's had higher hardness values at the first stage of experiments from 600 W to 1000 W attributed to the AlNi 3 phase and the BCC structure. 110 Nonetheless, there was a decline at the second stage of experiments from 1200 W to 1600 W with an average hardness ranging from 811 to 387 HV compared to AlCoCrFeNiCu HEA, which ranged from 389 to 837 HV after stage one and two of the experiments.…”

Cause of Angular Distortion in Fusion Welding: Asymmetric Cross-Sectional Profile along Thickness

“…Laser has been widely utilized in automatic welding for automotive, electronics, and aircrafts [28]. Laser welding is an attractive option because laser is stable and repeatable.…”