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Renjie Yang

Bio: Renjie Yang is an academic researcher. The author has contributed to research in topics: Heat-affected zone & Welding. The author has an hindex of 7, co-authored 10 publications receiving 141 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, a comparative study on the influence of fiber laser welding and CO2 laser welding on the weld bead geometry and the microstructure of fusion zone (FZ) of Inconel 617 was investigated.

47 citations

Journal ArticleDOI
Wenjie Ren1, Fenggui Lu1, Renjie Yang, Xia Liu, Zhuguo Li1 
TL;DR: In this paper, the authors investigated liquation cracking in the fiber laser welding Inconel 617 joint under different heat input and preheating conditions and found that the continuous (Cr, Mo)-rich phase is re-solidified due to the continuous liquid film along GBs during solidification.

44 citations

Journal ArticleDOI
Wen Liu1, Fenggui Lu1, Renjie Yang, Xinhua Tang1, Haichao Cui1 
TL;DR: In this article, the microstructure of different simulated HAZs was characterized by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscopy (TEM).

38 citations

Journal ArticleDOI
TL;DR: In this paper, the fracture toughness and related microstructure characteristics of dissimilarly welded joint manufactured by advanced 9Cr and CrMoV steels were systematically investigated for different regions including weld metal (WM), heat affected zone (HAZ) of 9Cr side (9Cr-HAZ), and 9Cr base metal (BM).
Abstract: In this paper, the fracture toughness and the related microstructure characteristics of dissimilarly welded joint manufactured by advanced 9Cr and CrMoV steels were systematically investigated. The dissimilarly welded joint was fabricated by narrow gap submerged arc welding (NG-SAW) applying multi-layer and multi-pass technique. Fracture toughness, as one of the most important property to assess the reliability of welded joint, was studied for different regions including CrMoV base metal (CrMoV-BM), heat affected zone (HAZ) of CrMoV side (CrMoV-HAZ), weld metal (WM), heat affected zone of 9Cr side (9Cr-HAZ) and 9Cr base metal (9Cr-BM). It was found that the fracture toughness of CrMoV-BM, CrMoV-HAZ and WM was better than that of 9Cr-HAZ and 9Cr-BM. In order to illustrate these results, the microstructure of the whole welded joint was observed by optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM) detailedly. It was found that the fine high-temperature tempered martensite and bainite in WM, CrMoV-BM and CrMoV-HAZ contribute to the higher fracture toughness, while lower fracture toughness for 9Cr-BM and HAZ was caused by coarse tempered lath-martensite. Furthermore, the fracture morphology showed that ductile fracture occurred in WM and CrMoV side, while brittle fracture appeared in BM and HAZ of 9Cr side.

35 citations

Journal ArticleDOI
TL;DR: In this article, the area fractions and average diameters of M23C6 carbides increased due to the long-range diffusion of Cr atoms at 950°C, while the impact energy values of weld metals exposed at 850°C increased because of a decrease of Cr in solution.

15 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the effects of major process parameters on build quality (porosity, residual stress, and composition changes) and materials properties (microstructure and microsegregation) are reviewed.

398 citations

Journal ArticleDOI
TL;DR: In this article, the authors describe the work performed on dissimilar laser welding of NiTi and CuAlMn shape memory alloys, superelastic at room temperature.

108 citations

Journal ArticleDOI
TL;DR: In this article, Gleeble thermal simulations were employed to investigate the influence of welding heat on grain morphology, carbide evolution, and mechanical properties of Inconel 625 alloys manufactured by selective laser melting.
Abstract: Strengthening the heat-affected zone in actual weld joint of Inconel 625 alloys was crucial for engineering applications in aerospace, petroleum, nuclear energy, and marine industries. In this study, Gleeble thermal simulations were employed to investigate the influence of welding heat on grain morphology, carbide evolution, and mechanical properties of Inconel 625 alloys manufactured by selective laser melting (SLM). Typical elongated columnar grains along the building direction and parallel columnar array with obvious layer boundaries along the scanning direction were observed in SLM-processed Inconel 625 alloys with hot isostatic processing treatment. After Gleeble thermal simulations, the prominent equiaxed grains appeared in the entire gauge region that was directly exposed to the simulated welding heat owing to the recrystallization process. Meanwhile, the size of equiaxed grains significantly increased with the increasing peak temperature. Particularly, only MC-type carbides were observed in the γ-Ni matrix before and after the thermal simulation owing to the fairly rapid heating (100 °C/s) and cooling (30 °C/s) process. Simulated welding heat produced a negative effect on the mechanical properties of the Inconel 625 alloys, especially for the peak temperature of 1350 °C. Then, the respective contributions of the four conventional strengthening mechanisms were successfully quantified for understanding the effect of the simulated peak temperature on the yield strength of the Inconel 625 alloys. Finally, the observations of microstructural evolution indicated that the cross-slip of dislocations was the dominant deformation mechanism to account for the large strain-hardening rate of the Inconel 625 alloys.

98 citations

Journal ArticleDOI
Yunpeng Mei1, Yongchang Liu1, Chenxi Liu1, Chong Li1, Liming Yu1, Qianying Guo1, Huijun Li1 
TL;DR: In this paper, the authors investigated the influence of welding speed and base metal grain size on the microstructures of EBW Inconel 718 and found that the weld shape transforms from a stemless wine glass shape to a nail head shape with the increase of the grain size of base metal.

94 citations

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the impact of welding current on the depth of penetration and depth to width (D/W) ratio of Inconel 718 and S.S. 316L by Tungsten Inert Gas (TIG) welding process.

63 citations