scholarly journals Characterization of Grain Size in 316L Stainless Steel Using the Attenuation of Rayleigh Wave Measured by Air-Coupled Transducer

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1901
Author(s):  
Meng Wang ◽  
Yangguang Bu ◽  
Zhaojie Dai ◽  
Shengyang Zeng
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Rayleigh Wave ◽  
Longitudinal Wave ◽  
Attenuation Coefficient ◽  
Rayleigh Waves ◽  
316L Stainless Steel ◽  
Wave Attenuation ◽  
Heat Treated ◽  
Comparison Results

Grain size is an important parameter in evaluating the properties of microstructures in metals. In this paper, the attenuation coefficient of Rayleigh waves is introduced to characterize grain size in heat treated 316L stainless steel. Rayleigh wave attenuation is measured using an angle beam wedge transducer as the transmitter and an air-coupled transducer as the receiver. The results show that the grain size in 316L stainless steel increases due to heat treatment time, the hardness decreases accordingly, and the attenuation coefficient of Rayleigh waves increases. This indicates that the Rayleigh wave attenuation is sufficient in distinguishing the changes in the properties of the heat-treated stainless steel. It is found that compared with the measurement method using an angle beam wedge receiver, the measured results are efficient, more stable and less influenced by the surface state when an air-coupled receiver is used. In addition, comparison results also show that the Rayleigh wave attenuation is more sensitive to changes in material properties than the longitudinal wave attenuation, as the wavelength of the Rayleigh wave is shorter than that of the longitudinal wave at the same frequency.

Corrosion behavior of cold-rolled and post heat-treated 316L stainless steel in 0.9wt% NaCl solution

2021 ◽  
Vol 28 (3) ◽  
pp. 440-449
Author(s):  
K. Bin Tayyab ◽  
A. Farooq ◽  
A. Ahmed Alvi ◽  
A. Basit Nadeem ◽  
K. M. Deen
Keyword(s):  
Stainless Steel ◽  
Corrosion Behavior ◽  
316L Stainless Steel ◽  
Nacl Solution ◽  
Heat Treated ◽  
Cold Rolled

Joining of Dissimilar 6063 Aluminium Alloy – 316L Stainless Steel by Spot Welding: Tensile Shear Strength and Heat Treatment

2013 ◽  
Vol 795 ◽  
pp. 492-495 ◽  
Author(s):  
Mohd Noor Mazlee ◽  
Alvin Tan Yin Zhen ◽  
Shamsul Baharin Jamaludin ◽  
Nur Farhana Hayazi ◽  
Shaiful Rizam Shamsudin
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Shear Strength ◽  
Spot Welding ◽  
316L Stainless Steel ◽  
Welding Current ◽  
Tensile Shear Strength ◽  
Tensile Shear ◽  
Heat Treated ◽  
6063 Aluminum Alloy

Tensile shear strength and ageing treatment of dissimilar 6063 aluminum alloy-316L stainless steel joint fabricated by spot welding were investigated. The results showed that tensile shear strength increased with the increasing of welding current. The enhancement of tensile shear strength of the joints was due to the enlargement of the nugget diameter. It was also found that the tensile shear strength values for heat treated joint almost similar to that of non-heat treated joint.

Effect of post-heat treatment cooling on microstructure and mechanical properties of selective laser melting manufactured austenitic 316L stainless steel

2020 ◽  
Vol 26 (10) ◽  
pp. 1739-1749
Author(s):  
Saad Waqar ◽  
Jiangwei Liu ◽  
Qidong Sun ◽  
Kai Guo ◽  
Jie Sun
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
316L Stainless Steel ◽  
Laser Melting ◽  
Content Type ◽  
Post Annealing ◽  
Cooling Conditions ◽  
Microstructure And Mechanical Properties ◽  
Heat Treated

Purpose This paper aims to investigate the influence of different post-annealing cooling conditions, i.e. furnace cooling (heat treatment (HT) 1 – slow cooling) and air cooling (HT 2 – fast cooling), on the microstructure and mechanical properties of selective laser melting (SLM) built austenitic 316L stainless steel (SS). Design/methodology/approach Three sets of 316L SS samples were fabricated using a machine standard scanning strategy. Each set consists of three tensile samples and a cubic sample for microstructural investigations. Two sets were subsequently subjected to annealing HT with different cooling conditions, i.e. HT 1 and HT 2, whereas one set was used in the as-built (AB) condition. The standard metallographic techniques of X-ray diffraction, scanning electron microscopy and electron back-scattered diffraction were used to investigate the microstructural variations induced by different cooling conditions. The resultant changes in mechanical properties were also investigated. Findings The phase change of SLM fabricated 316L was observed to be independent of the investigated cooling conditions and all samples consist of austenite phase only. Both HT 1 and HT 2 lead to dissolved characteristic melt pools of SLM. Noticeable increase in grain size of HT 1 and HT 2 samples was also observed. Compared with AB samples, the grain size of HT 1 and HT 2 was increased by 12.5% and 50%, respectively. A decreased hardness and strength, along with an increased ductility was also observed for HT 2 samples compared with HT 1 and AB samples. Originality/value From previous studies, it has been noticed that most investigations on HT of SLM fabricated 316L were mainly focused on the HT temperature or holding time. However, the post-HT cooling rate is also an equally important factor in deciding the microstructure and mechanical properties of heat-treated components. Therefore, this paper investigates the influence of different post-annealing cooling conditions on microstructure and mechanical properties of SLM fabricated 316L components. This study provides a foundation for considering the post-HT cooling rate as an influential parameter that controls the properties of heat-treated SLM components.

Application of Ultrasonic Inspection for Microstructure Analysis of Stainless Steel Grade 304L

2019 ◽  
Vol 798 ◽  
pp. 32-37
Author(s):  
Kittichai Sojiphan ◽  
Phongsathon Wangsupangkul ◽  
Tanapat Chailampangsuksakul
Keyword(s):  
Stainless Steel ◽  
Attenuation Coefficient ◽  
Ultrasonic Inspection ◽  
Correlation Study ◽  
Polycrystalline Materials ◽  
Destructive Testing ◽  
Electron Backscattered Diffraction ◽  
Heat Treated ◽  
Mechanical Waves ◽  
Non Destructive

Ultrasonic inspection is one of the most widely used non-destructive testing methods for inspection of fabricated structures and components. During ultrasonic inspection, mechanical waves in form of ultrasound are transmitted and propagate through volume of parts or components and reflect when the waves meet with the existing interface such as flaws in the welds. In addition to detection of flaws or defects within the structures, ultrasonic inspection is also used for determination of component thickness as well as characterization of microstructure of different materials. As the ultrasound is transmitted through media, the loss of ultrasound amplitude is referred to as acoustic attenuation. This attenuation effects greatly result from heterogeneity, anisotropy, and different grain sizes of crystalline media the ultrasound goes through. In order to develop the ultrasonic backscattering models for polycrystalline materials, experimental results of the correlation between the changes in attenuation coefficient and the actual microstructure of polycrystalline materials are necessary. This research article presents the preliminary results of this correlation study in stainless steel 304L specimens in as-received conditions compared with different annealed and heat-treated conditions. Such correlations of attenuation coefficient, hardness, and grain size will be used as baseline for future additional characterization technique such as electron backscattered diffraction to better understand the attenuation effects for textured polycrystalline materials.

Effect of Temperature and Grain Size on the Corrosion Behavior of 316L Stainless Steel in Seawater

2011 ◽  
Vol 299-300 ◽  
pp. 175-178 ◽  
Author(s):  
Sen Sen Xin ◽  
Jian Xu ◽  
Feng Jun Lang ◽  
Mou Cheng Li
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Corrosion Behavior ◽  
316L Stainless Steel ◽  
Seawater Temperature ◽  
Effect Of Temperature ◽  
Coarse Grain ◽  
Pitting Potential ◽  
Fine Grain ◽  
Different Grain Size

The corrosion behavior of 316L stainless steel was investigated in seawater at different temperature by using cyclic anodic polarization. The results indicated that two 316L specimens with different grain size showed similar pitting potential at 25°C. The increase of seawater temperature led to the linear decrease of pitting potential and repassivation potential. Because the pitting resistance of fine grain steel reduced larger than that of coarse grain steel with increasing temperature, the latter had a higher pitting potential about 60 mV at 85°C. Compared with the coarse grain steel, the fine grain steel showed a longer induction time for pitting at 65°C.

scholarly journals Elucidating the Effect of Bimodal Grain Size Distribution on Plasticity and Fracture Behavior of Polycrystalline Materials

2020 ◽  
Vol 11 (04) ◽  
pp. 2050007
Author(s):  
Fabrice Barbe ◽  
Ivano Benedetti ◽  
Vincenzo Gulizzi ◽  
Mathieu Calvat ◽  
Clément Keller
Keyword(s):  
Grain Size ◽  
Stainless Steel ◽  
Tensile Properties ◽  
Fracture Behavior ◽  
316L Stainless Steel ◽  
Scale Model ◽  
Coarse Grain ◽  
Polycrystalline Materials ◽  
Element Modeling ◽  
Bimodal Grain Size

The refinement of grains in a polycrystalline material leads to an increase in strength but as a counterpart to a decrease in elongation to fracture. Different routes are proposed in the literature to try to overpass this strength-ductility dilemma, based on the combination of grains with highly contrasted sizes. In the simplest concept, coarse grains are used to provide relaxation locations for the highly stressed fine grains. In this work, a model bimodal polycrystalline system with a single coarse grain embedded in a matrix of fine grains is considered. Numerical full-field micro-mechanical analyses are performed to characterize the impact of this coarse grain on the stress-strain constitutive behavior of the polycrystal: the effect on plasticity is assessed by means of crystal plasticity finite element modeling [B. Flipon, C. Keller, L. Garcia de la Cruz, E. Hug and F. Barbe, Tensile properties of spark plasma sintered AISI 316L stainless steel with unimodal and bimodal grain size distributions, Mater. Sci. Eng. A 729 (2018) 248–256] while the effect on intergranular fracture behavior is studied by using boundary element modeling [I. Benedetti and V. Gulizzi, A grain-scale model for high-cycle fatigue degradation in polycrystalline materials, Int. J. Fract. 116 (2018) 90–105]. The analysis of the computational results, compared to the experimentally characterized tensile properties of a bimodal 316L stainless steel, suggests that the elasto-plastic interactions taking place prior to micro-cracking may play an important role in the mechanics of fracture of this steel.

scholarly journals Effect of Annealing Heat Treatment on the Microstructural Evolution and Mechanical Properties of Hot Isostatic Pressed 316L Stainless Steel Fabricated by Laser Powder Bed Fusion

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 753 ◽  
Author(s):  
Kanwal Chadha ◽  
Yuan Tian ◽  
John Spray ◽  
Clodualdo Aranas
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Stainless Steel ◽  
316L Stainless Steel ◽  
Hot Isostatic Pressing ◽  
Isostatic Pressing ◽  
Heat Treated ◽  
Two Samples ◽  
Annealing Heat Treatment ◽  
Annealing Heat

In this work, the microstructural features and mechanical properties of an additively manufactured 316L stainless steel have been determined. Three types of samples were characterized: (i) as printed (AP), (ii) annealing heat treated (AHT), and (iii) hot isostatic pressed and annealing heat treated (HIP + AHT). Microstructural analysis reveals that the AP sample formed melt pool boundaries with nano-scale cellular structures. These structures disappeared after annealing heat treatment and hot isostatic pressing. The AP and AHT samples have similar grain morphologies; however, the latter has a lower dislocation density and contains precipitates. Conversely, the HIP + AHT sample displays polygon-shaped grains with twin structures; a completely different morphology compared to the first two samples. Optical micrography reveals that the application of hot isostatic pressing reduces the porosity generated after laser processing. The tensile strengths of all the samples are comparable (about 600 MPa); however, the elongation of the HIP + AHT sample (48%) was superior to that of other two samples. The enhanced ductility of the HIP + AHT sample, however, resulted in lower yield strength. Based on these findings, annealing heat treatment after hot isostatic pressing was found to improve the ductility of as-printed 316L stainless steel by as much as 130%, without sacrificing tensile strength, but the sample may have a reduced (40%) yield strength. The tensile strength determined here has been shown to be higher than that of the hot isostatic pressed, additively manufactured 316L stainless steel available from the literature.

Effect on corrosion resistance of microstructure of 316L austenitic stainless steel subjected to combined torsion–tension deformation

2020 ◽  
Vol 111 (5) ◽  
pp. 405-415
Author(s):  
Jidong Zhang ◽  
Weixue Han ◽  
Wenliang Rui ◽  
Jinghui Li ◽  
Zhenyi Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
316L Stainless Steel ◽  
Tensile Deformation ◽  
Deformation Twins ◽  
Transmission Electron ◽  
316L Austenitic Stainless Steel

Abstract The influences of combined torsion-tension deformation on the microstructural evolution and corrosion resistance of 316L stainless steel were investigated. The microstructure and corrosion behavior of the deformation samples were studied in detail. The results showed that the grains were more significantly refined under combined deformation than under tensile deformation. However, further increase in pre-torsion led to little change in grain size. The results of transmission electron microscopy and corrosion tests results indicated that high-density dislocations were detrimental, whereas the corrosion resistance, grain refinement and deformation twins were beneficial to corrosion resistance. Furthermore, the effect of deformation twins on corrosion resistance was greater than that of dislocation density, which, in turn, was greater than the influence of grain size.

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