Microstructures and Electrochemical Dissolution Characteristics of Additive-Manufactured Stainless Steel 304 on Different Sections at Low Current Density

2021 ◽  
Author(s):  
Chenhao Zhao ◽  
Ningsong Qu ◽  
Xiaochuan Tang
Keyword(s):  
Stainless Steel ◽  
Current Density ◽  
Electrochemical Dissolution ◽  
Stainless Steel 304

scholarly journals Electrodeposition of Co-Ni-Fe on Stainless Steel Bolts

2018 ◽  
Vol 7 (4.26) ◽  
pp. 221 ◽  
Author(s):  
M. S. Md.Nor ◽  
Z. Salleh ◽  
N. R. N. M. Masdek ◽  
Y. M Taib ◽  
M. Z. Abu
Keyword(s):  
Stainless Steel ◽  
Current Density ◽  
Deposition Time ◽  
Surface Hardness ◽  
Nickel Iron ◽  
Optimum Parameters ◽  
Cobalt Nickel ◽  
Stainless Steel 304 ◽  
Steel Bolts ◽  
Fe Ions

In a fastening system, bolt is the first component to be susceptible to corrosive attack. The focus of the study is to investigate the feasibility of coating stainless steel 304 bolts and the coating properties obtained. In this study, the bolts were coated with cobalt-nickel-iron (Co-Ni-Fe) alloy through electrodeposition using platinized titanium as the anodes. The temperature used was 50°C and the pH of the sulphate solution were 2. The current density was 96.68 mA/cm2 and deposition time was 30 minutes. The optimum electrodeposition parameters were studied through trial and error. The characteristics of coating such as elemental percentage and microhardness were compared with the substrate. The optimum parameters obtained were current density of 145.01 mA/cm2, temperature of 60°C and 30 minutes of deposition time. The suitable substrate orientation was horizontally hanged and rotated 60° around screw axis for every 5 minutes. The mean thickness of coating was 117.4 µm. The coating exhibited 25% hardness improvement over the substrate. The 2 litres solution could be used for 7.5 hours (15 plating cycles) to produce 15 samples. As a conclusion the surface hardness was not compromised despite that Co-Ni-Fe ions had depleted in the solution. 

EXPLOSIVE CLADDING OF ALUMINIUM 5052-STAINLESS STEEL 304

2019 ◽  
Vol 14 (3) ◽  
Author(s):  
Saravanan S ◽  
Murugan G
Keyword(s):  
Stainless Steel ◽  
Interfacial Microstructure ◽  
Bend Angle ◽  
Flyer Plate ◽  
Layer Formation ◽  
Molten Layer ◽  
Explosive Cladding ◽  
Plate Velocity ◽  
Stainless Steel 304 ◽  
Loading Ratio

This study addresses the effect of process parameters viz., loading ratio (mass of explosive/mass of flyer plate) and preset angle on dynamic bend angle, collision velocity and flyer plate velocity in dissimilar explosive cladding. In addition, the variation in interfacial microstructure and mechanical strength of aluminium 5052-stainless steel 304 explosive clads is reported. The interface exhibits a characteristic undulating interface with a continuous molten layer formation. The interfacial amplitude increases with the loading ratio and preset angle. Maximum hardness is observed at regions closer to the interface

Evaluation of the residual stress in stainless steel 304L hydraulically expanded joints

2020 ◽  
pp. 095440892096401
Author(s):  
Ying Hong ◽  
Xuesheng Wang ◽  
Yan Wang ◽  
Zhao Zhang ◽  
Yong Han
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Yield Strength ◽  
Residual Stresses ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
The Finite Element Method ◽  
Power Stations ◽  
Stainless Steel 304 ◽  
Initial Clearance

Stainless steel 304 L tubes are commonly used in the fabrication of heat exchangers for nuclear power stations. The stress corrosion cracking (SCC) of 304 L tubes in hydraulically expanded tube-to-tubesheet joints is the main reason for the failure of heat exchangers. In this study, 304 L hydraulically expanded joint specimens were prepared and the residual stresses of a tube were evaluated with both an experimental method and the finite element method (FEM). The residual stresses in the outer and inner surfaces of the tube were measured by strain gauges. The expanding and unloading processes of the tube-to-tubesheet joints were simulated by the FEM. Furthermore, an SCC test was carried out to verify the results of the experimental measurement and the FEM. There was good agreement between the FEM and the experimental results. The distribution of the residual stress of the tube in the expanded joint was revealed by the FEM. The effects of the expansion pressure, initial tube-to-hole clearance, and yield strength of the tube on the residual stress in the transition zone that lay between the expanded and unexpanded region of the tube were investigated. The results showed that the residual stress of the expanded joint reached the maximum value when the initial clearance was eliminated. The residual stress level decreased with the decrease of the initial tube-to-hole clearance and yield strength. Finally, an effective method that would reduce the residual stress without losing tightness was proposed.

A Noncyclic Method for Determination of Accumulated Strain in Stainless Steel 304 Pressure Vessels

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Gongfeng Jiang ◽  
Gang Chen ◽  
Liang Sun ◽  
Yiliang Zhang ◽  
Xiaoliang Jia ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
Peak Stress ◽  
Pressure Vessels ◽  
Experimental Results ◽  
Elastic Domain ◽  
Ratcheting Strain ◽  
Stainless Steel 304 ◽  
Accumulated Strain

Experimental results of uniaxial ratcheting tests for stainless steel 304 (SS304) under stress-controlled condition at room temperature showed that the elastic domain defined in this paper expands with accumulation of plastic strain. Both ratcheting strain and viscoplastic strain rates reduce with the increase of elastic domain, and the total strain will be saturated finally. If the saturated strain and corresponded peak stress of different experimental results under the stress ratio R ≥ 0 are plotted, a curve demonstrating the material shakedown states of SS304 can be constituted. Using this curve, the accumulated strain in a pressure vessel subjected to cyclic internal pressure can be determined by only an elastic-plastic analysis, and without the cycle-by-cycle analysis. Meanwhile, a physical experiment of a thin-walled pressure vessel subjected to cyclic internal pressure has been carried out to verify the feasibility and effectiveness of this noncyclic method. By comparison, the accumulated strains evaluated by the noncyclic method agreed well with those obtained from the experiments. The noncyclic method is simpler and more practical than the cycle-by-cycle method for engineering design.

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