Microstructure and mechanical properties of the 316 stainless steel nuclear grade experimental component made by wire and arc additive manufacturing

2020 ◽  
Vol 234 (21) ◽  
pp. 4258-4267
Author(s):  
Changqing Ye ◽  
Guangyao Lu ◽  
Xiangyang Peng ◽  
Shuo Hou ◽  
Jianming Zhou ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Tensile Properties ◽  
Nuclear Industry ◽  
Nuclear Grade ◽  
Delta Ferrite ◽  
Technical Requirements ◽  
Stainless Steel 316 ◽  
The Impact

An experimental component of nuclear grade austenitic stainless steel 316 (SS316) shielding plate was manufactured by wire and arc additive manufacturing (WAAM) method. Its microstructure, tensile properties at room and high temperatures, Vickers hardness, and impact properties were analyzed. The results show that the microstructure of WAAM SS316 product is mainly composed of austenite (γ) and delta-ferrite (δ) phases. The δ exhibits a fine vermicular morphology in the austenite matrix and is distributed at the boundaries of and inside the grains. The tensile properties of WAAM SS316 product are comparable to those of wrought SS316 and exceed the corresponding requirements of the nuclear industry. WAAM SS316 product has good uniform impact toughness in all directions, and the impact energy can fully meet the technical requirements of the nuclear industry with excellent performance. The results of nondestructive testing show that the quality of the WAAM SS316 shield plate product meets the evaluation requirements of the nuclear industry.

Mechanical Testing of Additive Manufactured Metal Parts

2015 ◽  
Vol 651-653 ◽  
pp. 713-718 ◽  
Author(s):  
Marion Merklein ◽  
Raoul Plettke ◽  
Daniel Junker ◽  
Adam Schaub ◽  
Bhrigu Ahuja
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Stainless Steel ◽  
Additive Manufacturing ◽  
Laser Beam ◽  
Round Robin Test ◽  
Metal Parts ◽  
Laser Beam Melting ◽  
Made In

The quality of additive manufactured parts however depends pretty much on the workers experience to control porosity, layer linkage and surface roughness. To analyze the robustness of the Laser Beam Melting (LBM) process a Round Robin test was made in which specimens from four institutes from different countries were tested and compared. For the tests each institute built a set of specimens out of stainless steel 1.4540. The aim of this work is to analyze the influence of the process parameters on the mechanical properties. The results show that there is a high potential for additive manufacturing but also a lot of further research is necessary to optimize this technology.

Probabilistic Models of Reliability of Cast Austenitic Stainless Steel Piping

2011 ◽  
Author(s):  
Haiyang Qian ◽  
David Harris ◽  
Timothy J. Griesbach
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Tensile Properties ◽  
Nuclear Power ◽  
Power Plants ◽  
Probabilistic Models ◽  
Probabilistic Approach ◽  
Delta Ferrite ◽  
Steel Piping

Thermal embrittlement of cast austenitic stainless steel piping is of growing concern as nuclear power plants age. The difficulty of inspecting these components adds to the concerns regarding their reliability, and an added concern is the presence of known defects introduced during the casting fabrication process. The possible presence of defects and difficulty of inspection complicate the development of programs to manage the risk contributed by these embrittled components. Much work has been done in the past to characterize changes in tensile properties and fracture toughness as functions of time, temperature, composition, and delta ferrite content, but this work has shown a great deal of scatter in relationships between the important variables. The scatter in material correlations, difficulty of inspection and presence of initial defects calls for a probabilistic approach to the problem. The purpose of this study is to describe a probabilistic fracture mechanics analysis of the maximum allowable flaw sizes in cast austenitic stainless steel piping in commercial power reactors. Attention is focused on fully embrittled CF8M material, and the probability of failure for a given crack size, load and composition is predicted considering scatter in tensile properties and fracture toughness (fracture toughness is expressed as a crack growth resistance relation in terms of J-Δa). Random loads can also be included in the analysis, with results generated by Monte Carlo simulation. This paper presents preliminary results for CF8M to demonstrate the sensitivity of key input variables. The outcome of this study is the flaw sizes (length and depth) that will fail with a given probability when a given load is applied.

Crack Repair Using Hybrid Additive Manufacturing and Friction Stir Processing

2019 ◽  
Author(s):  
Fadi Al-Badour ◽  
Ibrahim H. Zainelabdeen ◽  
Rami K. Suleiman ◽  
Akeem Adesina
Keyword(s):  
Additive Manufacturing ◽  
Friction Stir Processing ◽  
Welding Speed ◽  
Rotational Speed ◽  
Hardness Test ◽  
Mechanical Tests ◽  
Friction Stir ◽  
Al 6061 ◽  
The Impact

Abstract A hybrid additive manufacturing (AM) and friction stir processing (FSP) was used to heal a crack in 6 mm thick Al 6061-T6 aluminum alloy. AL-6061 is usually used in H2 high-pressure vessel fabrication as well as aerospace applications. In this work, Al-Si powder was utilized to fill the crack, then FSP was applied to consolidate and stir the powder with the base metal to fill and close the crack zone. Effect of FSP parameters including welding speed and tool rotation speed on the quality of repair was studied. Various mechanical tests, as well as characterization techniques such as hardness test, optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS), were employed to study the newly developed hybrid process on the quality of the repair. The investigation revealed that low rotational speed of 800 rpm results in minimum variation in microhardness. Moreover, the impact of welding speed on microhardness is smaller as compared to rotational speed.

scholarly journals Directed Energy Deposition of AISI 316L Stainless Steel Powder: Effect of Process Parameters

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 932
Author(s):  
Alberta Aversa ◽  
Giulio Marchese ◽  
Emilio Bassini
Keyword(s):  
Stainless Steel ◽  
Tensile Properties ◽  
Energy Deposition ◽  
316L Stainless Steel ◽  
Aisi 316L ◽  
Aisi 316L Stainless Steel ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Building Parameters

During Laser Powder-Directed Energy Deposition (LP-DED), many complex phenomena occur. These phenomena, which are strictly related to the conditions used during the building process, can affect the quality of the parts in terms of microstructural features and mechanical behavior. This paper investigates the effect of building parameters on the microstructure and the tensile properties of AISI 316L stainless-steel samples produced via LP-DED. Firstly, the building parameters were selected starting from single scan tracks by studying their morphology and geometrical features. Next, 316L LP-DED bulk samples built with two sets of parameters were characterized in terms of porosity, geometrical accuracy, microstructure, and mechanical properties. The tensile tests data were analyzed using the Voce model and a correlation between the tensile properties and the dislocation free path was found. Overall, the data indicate that porosity should not be considered the unique indicator of the quality of an LP-DED part and that a mechanical characterization should also be performed.

Welder learning curves behaviour: “focus on welding productivity with the TIG process of marine platforms stainless steel pipes”

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bruno Sobral Macedo ◽  
Miguel Luiz Ribeiro Ferreira
Keyword(s):  
Stainless Steel ◽  
Learning Curves ◽  
Superior Performance ◽  
Content Type ◽  
Average Productivity ◽  
Productivity Data ◽  
Asme Code ◽  
The Impact ◽  
Welding Productivity

PurposeThe purpose of the study is to analyse the feasibility of using the potential and exponential curve models to assess the learning of a group of welders, when welding stainless steel piping with the tungsten inert gas process.Design/methodology/approachThe welding productivity data grouped according to the requirements of the ASME SECTION IX code is organised into two groups: average productivity and baseline productivity. When processing the adjustment to the two models, the Excel software Solver tool was used. The criteria for assessing the quality of the fit were: least squared method, Spearman's correlation coefficient and graphical method. The impact of the variation coefficient on the average productivity and the amplitude (difference between the minimum and maximum productivity) was also evaluated on the baseline productivity.FindingsThe curves elaborated based on the average productivity presented better quality of adjustment than those constructed from the baseline productivity. The potential and exponential models presented similar adjustment conditions, with the second having a slightly superior performance. There were no productivity gains due to learning in the studied time interval. The grouping of the average daily productivity data based on the diameter range established in the ASME code section IX presented satisfactory results, enabling its use by the industry.Originality/valueThere is no news of work on piping welding with this focus. The proposal to group the productivity data according to the degree of difficulty of execution established by the ASME code section IX, widely used in the industry, is a significant contribution to monitoring the evolution of learning. In the same way, the results allow to adopt the average productivity determined from the first 20 days of realisation of a project, as a reasonable indicator to estimate the future performance of the work, helping to correct deadlines during the realisation of a project.

scholarly journals The Impact of Salt on the Quality of Fresh Wheat Noodle

2017 ◽  
Vol 21 (2) ◽  
pp. 53-61 ◽  
Author(s):  
Yunfeng Hu ◽  
Jinjin Wei ◽  
Yuanyuan Chen
Keyword(s):  
Tensile Properties ◽  
Network Structure ◽  
Tensile Force ◽  
Salt Content ◽  
Cooking Time ◽  
Rheological Parameters ◽  
Internal Network ◽  
Stability Time ◽  
The Impact

AbstractThe purpose is to analyze the concentration-response relationship of salt on the rheological properties, cooking characteristic and microstructure of fresh noodle and investigate the influence rules of salt on rheological characteristics, cooking characteristics and microstructure of fresh noodle. The change rules of rheological parameters, cooking characteristics and microstructure were analyzed using the refined wheat flour as the experimental material, adding different proportion of salt (0 up to 5% weight on flour basis), making fresh noodles. Results showed that the dough formation time, stability time, the maximum tensile force and tensile range increased gradually, weakening degree and the best cooking time decreased gradually, in addition, the internal network structure was fine-meshed with the increase of salt content. But the tensile distance began to decline, the network structure became loose and the hole enlarged when adding amount surpassed 3%. Taken together, adding 3% of the salt can improve the quality of fresh noodle. Research conclusions: the right amount of salt can improve the opaque quality index and tensile properties, reduce water absorption and optimum cooking time, enhance the internal network structure; but excessive salt will reduce the tensile properties of noodles and cooking characteristics, black or even destroy the production of internal network structure.

scholarly journals The Impact of Independent Variables Surface Machining Duplex Stainless Steel on the Flank Wear

2020 ◽  
Vol 26 (1) ◽  
pp. 27-30
Author(s):  
Tomasz Dyl ◽  
Adam Charchalis ◽  
Mirosław Szyfelbain
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Surface Engineering ◽  
Flank Wear ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Surface Machining ◽  
The Impact

Surface engineering is important for carried out to improve the quality of the surface layer of the material. It is important that in special applications of corrosion resistant steel, low surface roughness is obtained. Duplex stainless steel is becoming more widely used for example in the petrochemical industry or shipbuilding. Duplex stainless steel is a material classified as difficult-to-cut. It is therefore important to investigate the impact of machining parameters on the durability and wear of a cutting tool. In the paper has determined the influence of variables machining: feed rate, depth of cut, cutting speed, on the maximum tool flank wear. Surface machining was carry out with carbide tipped inserts. The criterion of the smallest roughness and the highest wear was proposed.

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