Buckling-Induced Delamination of TiN Film on Stainless Steel in the Presence of Stress Concentration

2021 ◽  
Author(s):  
K. Jagannadham
Keyword(s):  
Stainless Steel ◽  
Stress Concentration ◽  
Tin Film

FATIGUE CRACK GROWTH BEHAVIOR OF STAINLESS STEEL COATED WITH TiN FILM

2012 ◽  
Vol 06 ◽  
pp. 282-287
Author(s):  
SATOSHI FUKUI ◽  
DAISUKE YONEKURA ◽  
RI-ICHI MURAKAMI
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Propagation ◽  
Crack Growth ◽  
Crack Propagation Rate ◽  
Propagation Rate ◽  
Crack Growth Behavior ◽  
Tin Film

In our previous study, we examined the influence of the fatigue properties of the stainless steel coated with TiN film and clarified the influence of TiN coating and the surface roughness on the fatigue property. In this study, the four point bending fatigue crack growth tests were carried out for martensitic stainless steel coated with TiN film deposited by arc ion plating method in order to investigate the effect of surface finishing on the fatigue crack behavior for film coated material. The fatigue crack growth behavior was evaluated using the replica method. As a result, the crack propagation rate of mirror polished specimens were lower than that of rough surface specimens. The crack propagation rate was especially decreased for TiN coatings deposited on the mirror polished substrate. The surface roughness near the crack initiation site increased after fatigue test. It concludes that the surface roughness of substrate influences crack propagation rate and the deposition of TiN film affected influenced crack propagation rate and fatigue strength when the surface roughness of substrate is small enough.

Quantification of strain-induced martensite in 304L stainless steel in the presence of stress concentration

2015 ◽  
Author(s):  
PEDRO PENA LEITE ◽  
GLÁUCIO SOARES DA FONSECA ◽  
PAULO JUNIOR FARIA BERTUCI ◽  
MARCELO COSTA CARDOSO ◽  
Diego Gabriel Gomes Rosa
Keyword(s):  
Stainless Steel ◽  
Stress Concentration ◽  
304L Stainless Steel ◽  
Strain Induced Martensite

Evaluation of Environmental Effects on the Fatigue of Notched Specimen of Austenitic Stainless Steel Using Modified Rate Approach Method

2004 ◽  
Author(s):  
Katsumi Sakaguchi ◽  
Yasuhide Asada ◽  
Masao Itatani ◽  
Toshiyuki Saito
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Fatigue Life ◽  
Stress Concentration ◽  
Austenitic Stainless Steel ◽  
Notch Root ◽  
Notched Specimen ◽  
High Temperature Water ◽  
Approach Method ◽  
Temperature Water

Fatigue testing was conducted on notched specimens of austenitic stainless steel 316NG in high temperature water. Specimens were notched round bar with elastic stress concentration factors Kt of 1.4 and 3. For the specimen of Kt = 3, fatigue test was also performed in high temperature air. Environmental correction factor Fen recently proposed by Environmental Fatigue Tests (EFT) project in Japan Nuclear Safety Organization (JNES) was applied to the result of fatigue test to evaluate the environmental effects on fatigue life of notched specimen. Since the notch root strain varies non-proportionally to nominal strain in the elastic-plastic region, the modified rate approach method was applied to predict the fatigue life of notched specimen in the water, which was proposed to account for the environmental effect on fatigue life of nuclear component materials under varying conditions. Notch root strain and strain rate were calculated by FEM analysis. The difference between predicted and experimental fatigue lives in high temperature water was within factor of 2 for Kt = 3. The relationships between fictitious stress amplitude at notch root (= notch root strain amplitude multiplied by elastic modulus) and corrected fatigue life shows good coincidence with best fit curve for austenitic stainless steels. It is concluded that the modified rate approach method and current environmental correction factor Fen proposed by EFT project is applicable to predict fatigue life of the stress concentration when the notch root strain is adequately estimated.

Microstructure, Hardness, Adhesion and Corrosion Properties of Ti and TiN Films on Stainless Steel 316L

2020 ◽  
Vol 856 ◽  
pp. 66-75
Author(s):  
Kessaraporn Wathanyu ◽  
Karuna Tuchinda ◽  
Siriporn Daopiset ◽  
Sirinrath Sirivisoot ◽  
Surasak Surinphong
Keyword(s):  
Stainless Steel ◽  
Physical Vapor Deposition ◽  
Deposition Process ◽  
Stainless Steel 316L ◽  
Corrosion Properties ◽  
Tin Films ◽  
Tin Film ◽  
Coating Microstructure ◽  
The Difference ◽  
High Degree

Ti-based coating has been used for biomaterials to improve biocompatibility, mechanical and corrosion properties. Each coating shows unique performance depending on a variety of factors such as coating microstructure and properties as well as in-service conditions. In this study, the microstructure, surface topography, hardness, adhesion and corrosion properties of Ti and TiN films on stainless steel 316L coated by cathodic arc physical vapor deposition process (PVD) were studied. The results showed that the surface roughness of 316L increased after being coated with Ti and TiN film as evidenced by the numerous particles and voids observed on the surface of both films. The hardness of 316L coated with Ti and TiN was increased by approximately 50% and 85%, respectively. Ti and TiN coated samples showed good adhesion strength with the first critical load (LC1) of approximately 10N and 15N, respectively. However, the types of film failure for Ti and TiN were found to be different. Partial delamination with a high degree of plastic deformation was observed for Ti coating, whereas surface cracks were found for TiN coating. This finding is likely attributable to the difference in flow resistance and the amount of particles and voids observed. All samples showed a stable passive region during 7 days of immersion in Ringer’s solution. Ti film showed better corrosion resistance than TiN, which may have been caused by the effect of more voids on TiN surfaces formed by PVD coating.

scholarly journals CFRP Thin-Ply Fibre Metal Laminates: Influences of Ply Thickness and Metal Layers on Open Hole Tension and Compression Properties

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 910 ◽  
Author(s):  
Benedikt Kötter ◽  
Julian Karsten ◽  
Johann Körbelin ◽  
Bodo Fiedler
Keyword(s):  
Stainless Steel ◽  
Stress Concentration ◽  
High Stress ◽  
Image Correlation ◽  
Strength Increase ◽  
Stress Concentrations ◽  
Volume Fractions ◽  
Specific Strength ◽  
Compression Properties ◽  
Open Hole

Thin-ply laminates exhibit a higher degree of freedom in design and altered failure behaviour, and therefore, an increased strength for unnotched laminates in comparison to thick-ply laminates. For notched laminates, the static strength is strongly decreased; this is caused by a lack of stress relaxation through damage, which leads to a higher stress concentration and premature, brittle failure. To overcome this behaviour and to use the advantage of thin-ply laminates in areas with high stress concentrations, we have investigated thin-ply hybrid laminates with different metal volume fractions. Open hole tensile (OHT) and open hole compression (OHC) tests were performed with quasi-isotropic carbon fibre reinforced plastic (CFRP) specimens. In the area of stress concentration, 90° layers were locally substituted by stainless steel layers of differing volume fractions, from 12.5% to 25%. The strain field on the specimen surface was evaluated in-situ using a digital image correlation (DIC) system. The embedding of stainless steel foils in thin-ply samples increases the OHT strength up to 60.44% compared to unmodified thin-ply laminates. The density specific OHT strength is increased by 33%. Thick-ply specimens achieve an OHC strength increase up to 45.7%, which corresponds to an increase in density specific strength of 32.4%.

Fatigue Life Properties of Circumferentially-Notched Bar of Austenitic Stainless Steel With Various Concentration Factors

2018 ◽  
Author(s):  
Naoaki Nagaishi ◽  
Michio Yoshikawa ◽  
Saburo Okazaki ◽  
Hisao Matsunaga ◽  
Junichiro Yamabe ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Stress Concentration ◽  
Austenitic Stainless Steel ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Stress Ratio ◽  
Ambient Air ◽  
Fatigue Tests ◽  
Concentration Factors

Fatigue tests were performed using three types of round-bar specimens of Type 304, meta-stable, austenitic stainless steel. The specimens had circumferential notch with stress concentration factors, Kt, of 2, 3 or 6.6. Load controlled fatigue tests were conducted at stress ratio, R, of 0.1 and −1 in ambient air at room temperature. At R of 0.1, fatigue life was decreased with an increase in the stress concentration factor. Conversely, at R of −1, the stress concentration factor had little influence on the fatigue life. To understand the mechanism of the stress ratio effect, local deformation behavior at and beneath the notch root during the fatigue test was computed by means of finite element analysis considering that the plastic constitutive model describes the cyclic stress-strain response.

Study on the Fatigue Properties of the TIG Weld Joint with the Stainless Steel Conduit in Aircraft

2015 ◽  
Vol 664 ◽  
pp. 104-110
Author(s):  
Ying Liu ◽  
Dong Jie Li ◽  
Xiao Hong Li
Keyword(s):  
Stainless Steel ◽  
Stress Concentration ◽  
Crack Initiation ◽  
Crack Propagation ◽  
Weld Joint ◽  
Fatigue Cracks ◽  
Fatigue Properties ◽  
Research Focus ◽  
Weld Toe ◽  
Crack Initiation Life

The research focus on the material of the stainless steel thin conduit in aircraft, named 1Cr18Ni9Ti , and the TIG weld joint of which was investigated to analysis the fatigue properties. The fracture mechanics was used to analysis the crack initiation life and crack propagation life, and the fatigue surface was characterized with scanning electron microscope (SEM). The experimental and analytical results show that, the origin position of fatigue crack is the surface of the conduit. The stress concentration at the weld toe, the crystal structure is not uniform and Stress concentration in the heat affected zone (HAZ) and fusion line, so the fatigue cracks are easily generated in these locations. Delta K increases to a certain value, the HAZ has become one of the most dangerous position. The crack initiation life of HAZ in the total fatigue life is far higher than the proportion of crack propagation life.

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