Study on the interfacial characteristics and crack propagation of 630 stainless steel fabricated by hybrid additive manufacturing (additional DED building on L-PBFed substrate)

2022 ◽  
pp. 142657
Author(s):  
Tae Geon Kim ◽  
Gwang Yong Shin ◽  
Do Sik Shim
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Crack Propagation ◽  
Interfacial Characteristics

scholarly journals The Fracture Behavior of 316L Stainless Steel with Defects Fabricated by SLM Additive Manufacturing

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1542
Author(s):  
Hui Li ◽  
Jianhao Zhang
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Crack Propagation ◽  
316L Stainless Steel ◽  
Material Model ◽  
Multiple Crack ◽  
Micro Cracks ◽  
Void Defects ◽  
Fracture Behaviors ◽  
Pairwise Force

In this paper, the fracture behaviors of 316L stainless steel with defects fabricated by the Selective Laser Melting (SLM) additive manufacturing are studied by a peridynamic method. Firstly, the incremental formulations in the peridynamic framework are presented for the elastic-plastic problems. Then, the pairwise force of a bond for orthotropic material model is proposed according to both the local and the global coordinate systems. A simple three-step approach is developed to describe the void defects that generated in the processing of the SLM additive manufacturing in the numerical model. Next, some representative numerical examples are carried out, whose results explain the validation and accuracy of the present method, and demonstrate that the orthotropic features, micro-cracks and voids of the materials have a significant influence on the ultimate bearing capacity, crack propagation and branching of the corresponding structures. It is also revealed that the crack initiations are induced actively by the defects and the crack branching is contributed to the complex multiple-crack propagation. Finally, the achievements of this paper lay a foundation for the engineering applications of the SLM additive manufacturing materials.

Additive Manufacturing of 316L Stainless Steel by a Printing-Debinding-Sintering Method: Effects of Microstructure on Fatigue Property

2021 ◽  
Vol 143 (9) ◽  
Author(s):  
Dayue Jiang ◽  
Fuda Ning
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Additive Manufacturing ◽  
Fatigue Crack Growth ◽  
Crack Propagation ◽  
Crack Growth ◽  
316L Stainless Steel ◽  
High Energy ◽  
Fatigue Properties ◽  
Crack Growth Model

Abstract Additive manufacturing (AM) technology has been broadly applied to the fabrication of metallic materials. However, current approaches consume either high energy or large investment that considerably elevates their entry threshold. An economic extrusion-based AM method followed by debinding and sintering could efficiently produce the metal parts with relatively low cost and high material utilization. However, an in-depth analysis of the fatigue performance of the component built by such a technology has been little documented so far. Herein, the 316L stainless steel was fabricated throughout the printing-debinding-sintering (PDS) pathway and its fatigue properties were comprehensively assessed. Tensile and flexural fatigue tests were conducted to reveal the fatigue strength and fractural behaviors under different loading conditions, while the fatigue crack growth (FCG) test was performed to quantify the crack propagation. The results indicated the number of 105 cycles can be reached for the tensile specimens under the fatigue loading of 120 MPa, whereas 1.37 × 105 cycles were endured by the flexural specimens under 150 MPa. The fractural morphology indicated an adverse impact of the pore-induced voids on the tensile fatigue crack propagation, but such a drawback could be alleviated in the flexural loading condition. The FCG test unveiled the crack growth rate with the number of cycles and determined the material-related coefficients in the fatigue crack growth model. The research findings provided valuable insights into the effects of the PDS process and microstructures on the resultant fatigue properties of the metal component.

scholarly journals Parameters Optimization of Auxiliary Gas Process for Double-Wire SS316L Stainless Steel Arc Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 190
Author(s):  
Wei Wu ◽  
Jiaxiang Xue ◽  
Wei Xu ◽  
Hongyan Lin ◽  
Heqing Tang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Evaluation System ◽  
Gas Flow ◽  
Interactive Effect ◽  
Parameters Optimization ◽  
Heat Accumulation ◽  
Auxiliary Process ◽  
Strength And Stiffness

Serious heat accumulation limits the further efficiency and application in additive manufacturing (AM). This study accordingly proposed a double-wire SS316L stainless steel arc AM with a two-direction auxiliary gas process to research the effect of three parameters, such as auxiliary gas nozzle angle, auxiliary gas flow rate and nozzle-to-substrate distance on depositions, then based on the Box–Behnken Design response surface, a regression equation between three parameters and the total score were established to optimized parameters by an evaluation system. The results showed that samples with nozzle angle of 30° had poor morphology but good properties, and increasing gas flow or decreasing distance would enhance the airflow strength and stiffness, then strongly stir the molten pool and resist the interference. Then a diverse combination of auxiliary process parameters had different influences on the morphology and properties, and an interactive effect on the comprehensive score. Ultimately the optimal auxiliary gas process parameters were 17.4°, 25 L/min and 10.44 mm, which not only bettered the morphology, but refined the grains and improved the properties due to the stirring and cooling effect of the auxiliary gas, which provides a feasible way for quality and efficiency improvements in arc additive manufacturing.

Assessing the Co-Deformability of a Nickel-Based Superalloy-304L Stainless Steel Preform Manufactured through Laser Additive Manufacturing

2021 ◽  
Author(s):  
Dipti Samantaray ◽  
Bommakanti Aashranth ◽  
Neelakandapillai Lekshmanan Parthasarathi ◽  
Arun Kumar Rai ◽  
Marimuthu Arvinth Davinci ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
304L Stainless Steel ◽  
Laser Additive Manufacturing ◽  
Nickel Based Superalloy

scholarly journals Influence of Duty Ratio and Current Mode on Robot 316L Stainless Steel Arc Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 508
Author(s):  
Ping Yao ◽  
Hongyan Lin ◽  
Wei Wu ◽  
Heqing Tang
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Heat Input ◽  
Low Frequency ◽  
Single Pulse ◽  
Pulse Mode ◽  
Double Pulse ◽  
Duty Ratio ◽  
Utilization Rate ◽  
Specimen Height

Wire and arc additive manufacturing (WAAM) is usually for fabricating components due to its low equipment cost, high material utilization rate and cladding efficiency. However, its applications are limited by the large heat input decided by process parameters. Here, four 50-layer stainless steel parts with double-pulse and single-pulse metal inert gas (MIG) welding modes were deposited, and the effect of different duty ratios and current modes on morphology, microstructure, and performance was analyzed. The results demonstrate that the low frequency of the double-pulse had the effect of stirring the molten pool; therefore, the double-pulse mode parts presented a bigger width and smaller height, finer microstructure and better properties than the single-pulse mode. Furthermore, increasing the duty ratio from 35% to 65% enlarged the heat input, which then decreased the specimen height, increased the width, and decreased the hardness and the tensile strength.

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