Stress corrosion and mechanical properties of zinc coating on 304 stainless steel

2021 ◽  
Vol 63 (3) ◽  
pp. 209-218
Author(s):  
Hua Zhang ◽  
Sihan Zheng ◽  
Yue Wang ◽  
QiLiang Li ◽  
Jie Tao ◽  
...  

Abstract The effect of stress corrosion on the mechanical properties of the coating in the zinc coating/304 stainless steel substrate system was investigated by three-point bending, slow strain rate tensile (SSRT) and nano-indentation tests. Studies have shown that fracture toughness was improved when the coating was thick but weakened when the coating was thin. At varied coating thicknesses (80 μm, 160 μm, 240 μm, 320 μm, 400 μm), the decline rates of the fracture toughness were 77.48 %, 71.82 %, 66.67 %, 55.48 % and 51.52 %, respectively, and those for the critical strain of crack initiation were 94.97 %, 91.88 %, 88.42 %, 76.19 % and 74.33 %, respectively. In addition, simulations were made to analyze the crack propagation of zinc coating in coating/substrate system under tensile loading by ABAQUS, which proved the accuracy of the experiment.

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 583 ◽  
Author(s):  
Pengxian Zhang ◽  
Yibin Pang ◽  
Mingwei Yu

WC-reinforced Ni60 composite coatings with different types of WC particles were prepared on 304 stainless steel surface by laser cladding. The influences of spherical WC, shaped WC, and flocculent WC on the microstructures and properties of composite coatings were investigated. The results showed that three types of WC particles distribute differently in the cladding coatings, with spherical WC particles stacking at the bottom, shaped WC aggregating at middle and lower parts, with flocculent WC particles dispersing homogeneously. The hardnesses, wear resistances, corrosion resistances, and thermal shock resistances of the coatings are significantly improved compared with the stainless steel substrate, regardless of the type of WC that is added, and especially with regard to the microhardness of the cladding coating; the addition of spherical or shaped WC particles can be up to 2000 HV0.05 in some areas. Flocculent WC, shaped WC, and spherical WC demonstrate large to small improvements in that order. From the results mentioned above, the addition of flocculent WC can produce a cladding coating with a uniform distribution of WC that is of higher quality compared with those from spherical WC and shaped WC.


2017 ◽  
Vol 36 (8) ◽  
pp. 855-861
Author(s):  
Yong Pan ◽  
Junwei Cui ◽  
Weixin Lei ◽  
Jie Zhou ◽  
Zengsheng Ma

AbstractEffects of heat treatment on the mechanical properties of Ni films on 430 stainless steel substrate were investigated. The Ni films were annealed at heat treatment temperatures ranging from 0 °C to 800 °C for 2 h. The surface morphology, composition, and texture orientation of Ni films were studied by scanning electron microscopy, energy dispersive spectrometry, and X-ray diffraction. The load–indentation depth curves of Ni films before and after heat treatment were measured by using nanoindentation method. In conjunction with finite element modeling and dimensional analysis, the stress–strain relationships of Ni films on 430 stainless steel substrate at different temperatures are successfully obtained by using a power-law hardening model.


2013 ◽  
Vol 771 ◽  
pp. 35-40 ◽  
Author(s):  
Yi Dong Jin ◽  
Chao Yin Nie ◽  
Chun Hua Ran ◽  
Wen Zhu ◽  
Yang Zhao ◽  
...  

To improve adhesion strength of DLC coatings on 304 stainless steel substrate,we studied substrate pretreatment by electrolytic/chemical etching methods.In this study,The DLC coatings were deposited on two groups of 304 stainless steel which had been electrolytically and chemically etched separately. The morphology of the coatings and substrate were characterized by SEM and metalloscope. The surface roughness of substrate was measured by roughness tester .The result shows that adhesion strength of DLC coatings on 304 stainless steel substrate is improved obviously due to mechanical interlock,surface adsorption and stress release.With prolonging the etching time,the adhesion strength of DLC coatings on the chemically etched substrate increase firstly and then decrease. The adhesion strength of DLC coatings on electrolytically etched substrate continuously increase. DLC coatings on electrolytically etched substrate perform better than the one on chemically etched substrate in adhesion.This is caused by the different surface morphology.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6948
Author(s):  
Andrey Filippov ◽  
Nikolay Shamarin ◽  
Evgeny Moskvichev ◽  
Nikolai Savchenko ◽  
Evgeny Kolubaev ◽  
...  

Electron beam additive wire-feed deposition of Cu-7.5wt.%Al bronze on a stainless-steel substrate has been carried out at heat input levels 0.21, 0.255, and 0.3 kJ/mm. The microstructures formed at 0.21 kJ/mm were characterized by the presence of both zigzagged columnar and small equiaxed grains with 10% of Σ3 annealing twin grain boundaries. No equiaxed grains were found in samples obtained at 0.255 and 0.3 kJ/mm. The zigzagged columnar ones were only retained in samples obtained at 0.255 kJ/mm. The fraction of Σ3 boundaries reduced at higher heat input values to 7 and 4%, respectively. The maximum tensile strength was achieved on samples obtained with 0.21 kJ/mm as tested with a tensile axis perpendicular to the deposited wall’s height. More than 100% elongation-to-fracture was achieved when testing the samples obtained at 0.3 kJ/mm (as tested with a tensile axis coinciding with the wall’s height).


2021 ◽  
Author(s):  
Alpeshkumar Macwan

This study is aimed at identifying the change of residual stresses in suspension plasma sprayed (SPS) 8 mol% YSZ electrolytes on top of porous stainless steel substrate with varying processing parameters and temperatures. The residual stresses in the electrolyte layer are tensile with a value of approximately 90 MPa at room temperature. Porosity, microcracks and segmentation cracks are observed to form in the coating during post-deposition cooling. The decrease of residual stresses with increasing temperature is related to the changes in the Young’s modulus, thermal expansion mismatch, micro-defects and possible creeping of porous stainless steel substrate. The coating fabricated using a torch power of 133 kW and stand-off distance of 90 mm exhibits the highest residual stress due to the formation of a denser microstructure and less cracking. Furthermore, the fracture toughness and interface fracture toughness of the SPS YSZ coating at the optimized condition was determined and discussed.


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