Surface Roughness and Initial Pressure Effect on Superplastically Carburized Duplex Stainless Steel

2010 ◽  
Vol 297-301 ◽  
pp. 227-232 ◽  
Author(s):  
Sharidah Azuar Abdul Azis ◽  
Iswadi Jauhari ◽  
Nik Rozlin Nik Masdek ◽  
Nor Wahida Ahamad ◽  
Hiroyuki Ogiyama
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Surface Hardness ◽  
Direct Interaction ◽  
Initial Pressure ◽  
Pressure Effects ◽  
Superplastic Material ◽  
Coarse Microstructure ◽  
Effect Of Surface

Superplastic carburizing (SPC) is a carburizing process that combines carburizing with superplastic deformation. Since SPC involves direct interaction between the superplastically deformed surface and the solid carbon medium, the effect of surface roughness on the process cannot be disregarded. This paper presents the study of surface roughness and initial pressure effects on superplastic carburizing of duplex stainless steel (DSS). SPC was conducted under four different surface roughness (Ra) conditions of 0.9, 0.3, 0.1 and 0.03 μm. The microstructure, surface hardness, and carburized layer thickness were studied. Comparisons were also done on non-superplastic material which has a coarse microstructure. The results showed that the surface roughness strongly affected the properties of the superplastically carburized duplex stainless steel while its effects on the non-superplastic material were not that obvious.

The Effect of Surface Self-Nanocrystallization on Low-Temperature Gas Carburization for AISI 316L Steel

2019 ◽  
Vol 795 ◽  
pp. 137-144
Author(s):  
Zhe Liu ◽  
Ya Wei Peng ◽  
Jian Ming Gong ◽  
Chao Ming Chen
Keyword(s):  
Stainless Steel ◽  
Elastic Modulus ◽  
Austenitic Stainless Steel ◽  
Low Temperature ◽  
Surface Hardness ◽  
Electron Probe Micro Analyzer ◽  
Gas Carburizing ◽  
316L Steel ◽  
Negative Effect ◽  
Effect Of Surface

In this work, the effect of surface self-nanocrystallization on low-temperature gas carburizing for AISI316L austenitic stainless steel has been studied. The surface ultrasonic rolling processing (SURP) was used to prepare nanostructured surface layers, and then the un-SURP and SURP samples were treated by LTGC at 470 °C for 10 h, 20 h and 30 h. In order to analyze the effect of surface self-nanocrystallization on low-temperature gas carburizing, optical microscopy (OM), atomic force microscope (AFM), scanning electron probe micro-analyzer (EPMA) and nano-indentation analyzer were used. The results show depth of SURP-induced plastic deformation layer was about 330 μm. Meanwhile, the surface hardness and elastic modulus were increased but the surface roughness decreased obviously after SURP. After low-temperature gas carburizing, according to the results of the thickness, carbon concentration, nano-hardness and elastic modulus of the carburized layer, the conclusion is that surface self-nanocrystallization carried by SURP has a negative effect on the low-temperature gas carburizing for AISI316L austenitic stainless steel and with the increase of carburizing time, the greater the adverse effect on carburizing.

A Study on Boronizing of Duplex Stainless Steel

2006 ◽  
Vol 306-308 ◽  
pp. 887-892 ◽  
Author(s):  
Rafidah Hasan ◽  
Iswadi Jauhari ◽  
S.M. Yunus ◽  
Raden Dadan Ramdan ◽  
Nik Rozlin Nik Masdek
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Layer Thickness ◽  
Surface Hardness ◽  
Boride Layer ◽  
Grain Sizes ◽  
Fine Grain ◽  
Surface Contact

Boronizing is a method to increase the surface hardness of engineering components [1]. This is beneficial especially when the components are always in surface contact with other materials. In this study, boronizing treatment was successfully done on duplex stainless steel (DSS). Two types of DSS with different microstructure were boronized – the as-received DSS and the fine grain DSS. The morphology of boride layer formed on boronized DSS is compact and smooth. The boride layer thickness for both DSS ranged from 9 to 32 +m. Depending on boronizing time and temperature, the hardness of boronized fine grain DSS is between 1014 HV to 2601 HV. The values are higher than that of the as-received DSS which is between 797 HV to 2311 HV. The result shows that there is a different in hardness of boride layer for two different grain sizes of DSS although the layer thickness formed is about the same in depth.

Ultrasonic Cavitation Peening of Stainless Steel and Nickel Alloy

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Yibo Gao ◽  
Benxin Wu ◽  
Ze Liu ◽  
Yun Zhou ◽  
Ninggang Shen ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Nickel Alloy ◽  
Vibration Amplitude ◽  
Surface Hardness ◽  
Surface Profile ◽  
Ultrasonic Cavitation ◽  
Surface Microhardness ◽  
Workpiece Surface ◽  
Different Depths

Ultrasonic cavitation peening is a peening process utilizing the high pressure induced by ultrasonic cavitation in liquids (typically water). In this paper, ultrasonic cavitation peening on stainless steel and nickel alloy has been studied. The workpiece surface microhardness, the microhardness variation at different depths, the workpiece surface profile, roughness, and morphology have been measured or observed. It has been found that for the studied situations, ultrasonic cavitation peening (at a sufficiently high horn vibration amplitude) can obviously enhance the workpiece surface hardness without significantly increasing the surface roughness. Under the investigated conditions, a surface layer of more than around 50 μm has been hardened under a horn vibration amplitude of ∼20 μm.

scholarly journals Effect of Surface Characteristics of Different Implant Abutment Materials on the Microbial Adhesion- An Invitro Study

2021 ◽  
Author(s):  
Vimal Munot ◽  
Ramesh P Nayakar ◽  
Raghunath Patil
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Energy ◽  
Test Group ◽  
Surface Characteristics ◽  
Microbial Adhesion ◽  
Implant Abutment ◽  
Group B ◽  
Pair Wise Comparison ◽  
Effect Of Surface

Introduction: In two-stage implants, micro-gap between the fixture and the abutment and the superstructure are the potential areas to cause peri-implantitis. The surface roughness and surface energy of the implant abutment materials play an important role in the microbial colonisation on their surface and can help the clinician to choose a better implant abutment material in terms of microbial affinity. Aim: To evaluate the effect of surface characteristics of different implant abutment materials on microbial adhesion. Materials and Methods: The comprehensive analytical experimental study was conducted at KAHER KLE VK Institute of Dental Sciences, Belagavi between Jan 2017- Dec 2017. Forty-five (n=45) identical disc shaped specimens were fabricated using; Zirconia (Group A), Titanium alloy (Group B) and Surgical Grade Stainless Steel (Group C). The surface roughness was assessed for all test groups by Profilometer and Scanning Electron Microscope (SEM). The Surface energy was evaluated for all the test group specimens using Goniometer. Microbial adhesion and assessment were performed using sonicating and vortexing method for all the three groups using three different bacterial strains. The Colony Forming Units for all the specimens were tabulated and subjected to statistical analysis to draw the conclusions from the resultant data.The resultant data was analysed using SPSS software (Version 20). In order to collectively compare the means of the study groups pair-wise comparison of the test group was done using paired t-test with (p<0.05), and correlation between the surface parameters and CFU counts was done using Karl Pearson’s correlation coefficient. Results: On pair-wise comparison of three Groups (A, B, and C) with respect to surface roughness, there were statistically significant differences in surface roughness Ra values between all the groups p<0.001. On pair-wise comparison of all the three Groups with respect to surface energy, there were statistically significant differences in Wetting Angle (WA) values between all the groups (p<0.001**) except between group B and A (p=0.15). Zirconia showed the least CFU counts for Pi and Aa though the differences were not statistically significant. Karl Pearson’s correlation coefficient between surface roughness and surface energy with CFU counts showed a strongly positive correlation for all microbial species and were statistically significant p<0.001**. Conclusion: There was a strongly positive correlation of surface roughness and surface energy to CFU counts. Zirconia showed a low colonisation potential against P.intermedia and A.actinomycetemcomitans than titanium alloy and surgical grade stainless steel.

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