High-strength, low-alloy (HSLA) steel has attracted much attention in the manufacturing industry because of its good combination of high strength and toughness, low cost, and good formability. Wire and arc additive manufacturing (WAAM) technology can realize the rapid prototyping of HSLA steel parts. This study investigated a 26-layer HSLA steel component fabricated with the WAAM technique. The microstructure of the deposited wall of ER120S-G is mainly acicular ferrite, and there are longitudinal, preferentially growing dendrites along the deposition direction. With the deposition height accumulation, the top sample’s interlayer temperature increases and the amount of acicular ferrite in the microstructure decreases, while the amount of quasi-polygonal ferrite, Widmanstatten ferrite increases. The changes in microhardness were consistent with the corresponding microstructure gradients: the microhardness of the top sample showed a decreasing trend along the deposition direction, while the microhardness of the middle sample was uniform and stable. The present work shows that the mechanical properties of HSLA steel parts deposited using WAAM technology have good strength and toughness. The microstructure gradient of the sample along the deposition direction did not lead to a significant difference in the tensile strength of the sample at different heights. On the contrary, the ductility of the longitudinal sample is slightly lower than that of the transverse sample, indicating some anisotropy in the deposited sample, which is related to the directional growth of grains along the direction of heat flow. From the current work, the thin wall of HSLA steel prepared with the WAAM process has good mechanical properties, which indicates that it is feasible to replace the traditional processing method with the WAAM process to rapidly manufacture an HSLA steel structure meeting the performance requirements.

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Microstructure and Mechanical Properties of High-Strength, Low-Alloy Steel Thin-Wall Fabricated with Wire and Arc Additive Manufacturing

Study on the Interfacial Evolution and Mechanical Properties of the Cu/Sac105/Cu Solder Joint Modified by Si3n4 Nanowires

The Effect of Multiple Thermal Cycles on Ti-6Al-4V Deposits Fabricated by Wire-arc Directed Energy Deposition: Microstructure Evolution, Mechanical Properties, and Corrosion Resistance

Study on the interfacial evolution and mechanical properties of Cu/SAC105/Cu solder joint modified by Si3N4 nanowires

An efficient method to engage oxide ceramics in low-temperature interfacial reactions: Microstructure evolution and kinetics behaviors based on supercooling in a transient liquid phase bonding joint

A Low-Temperature Joining Technology Suitable for High-Temperature Applications Developed by Establishing Chemical Potential and Supercooling Gradients

Joining single crystal superalloy with polycrystalline superalloy has important applications in the aerospace industry. Here, the IC10 single crystal superalloy to GH536 polycrystalline superalloy was diffusion brazed using a BNi-2 filler alloy. The effects of bonding temperature and time on the microstructure evolution and mechanical properties of the GH536/IC10 joints were investigated in detail. The results elucidated that the joint brazed at a lower temperature and time (i.e., 1050 °C/30min) was composed of diffusion affected zone (DAZ), athermal solidification zone (ASZ), and isothermal solidification zone (ISZ). The secondary precipitates formed in DAZ were Cr-rich borides, Cr–Mo borides, and Cr–Mo–W borides. The ASZ was made up of Cr-rich borides, Ni-rich borides, Ni–Cr borides, and Ni-based solid solutions. These borides with high hardness were the potential source of cracks and caused the joints to fracture under a lower load. Raising bonding temperature and time gradually eliminated Ni-rich borides in ASZ and Cr-rich borides in DAZ, and improved the shear strength. 

Qiuguang Zhang

Papers

An efficient method to engage oxide ceramics in low-temperature interfacial reactions: Microstructure evolution and kinetics behaviors based on supercooling in a transient liquid phase bonding joint

A Low-Temperature Joining Technology Suitable for High-Temperature Applications Developed by Establishing Chemical Potential and Supercooling Gradients

Diffusion brazing of GH536 polycrystalline superalloy with IC10 single crystal superalloy using BNi-2 interlayer