scholarly journals MICROSTRUCTURE, MECHANICAL AND TRIBOLOGICAL BEHAVIOUR OF AISI 316L STAINLESS STEEL DURING SALT BATH NITRIDING

2021 ◽  
Vol 27 (2) ◽  
pp. 47-52
Author(s):  
Elhadj GHELLOUDJ
Keyword(s):  
Stainless Steel ◽  
Surface Hardness ◽  
Salt Bath ◽  
S Phase ◽  
Current Work ◽  
Tribological Characteristics ◽  
Aisi 316L ◽  
Surface Microstructures ◽  
The Impact ◽  
Salt Bath Nitriding

The aim of the current work was to analyse the impact of salt bath nitriding on the behavior of the tribological characteristics and surface microstructures of AISI 316L stainless steels. Nitriding was carried out at 580°C for 10 h. The tribological, structural behavior of the AISI 316L before and after salt bath nitriding was compared. The surface microstructures, tribological characteristics, as well as its surface hardness, were investigated using optical microscopy (OM), X-ray diffractometer (XRD), surface profilometer, pin-on-disk wear tester and microhardness tester. In the current work the experimental results showed that a great surface hardness could be achievable through salt bath nitriding technique because of the formation of the so-called expanded Austenite (S-phase), the nitrogen diffusion region. The surface hardness of AISI 316 stainless steel after nitriding process reached 1100 HV0.025 which was six times the untreated sample hardness. The S-phase is additionally expected to the improvement of wear resistance and decrease the friction coefficient.

scholarly journals EFFECT OF SALT BATH NITRIDING TIME ON THE PERFORMANCES OF 304 STAINLESS STEEL

2020 ◽  
Vol 26 (1) ◽  
pp. 4-6
Author(s):  
Xiliang LIU ◽  
Changjun MAO ◽  
Meihong WU ◽  
Wei CAI ◽  
Mingyang DAI ◽  
...  
Keyword(s):  
Weight Loss ◽  
Stainless Steel ◽  
Wear Resistance ◽  
Salt Bath ◽  
304 Stainless Steel ◽  
Micro Hardness ◽  
Untreated Sample ◽  
Nitriding Time ◽  
Optimal Duration ◽  
Salt Bath Nitriding

In this study, salt bath nitriding was carried out at 565℃ for various times for 304 stainless steel (304SS). The effect of salt bath nitriding time on the microstructure, micro-hardness and wear resistance was investigated systematically. The results showed a nitriding layer was formed during salt bath nitriding, and the thickness of effective hardening layer is duration dependant. The maximum microhardness value of 1200HV0.01 was obtained at optimal duration of 150min, which was five times higher than that of the untreated sample. And the wear resistance could be significantly improved by salt bath nitriding, the lowest weight loss after wear resistance was obtained while nitriding for 150min, which was one tenth of that of untreated sample.

Effect of Gas Content and Treatment Temperature on the Characteristic of Surface Layers of Low Temperature Plasma Nitrided 316L Austenitic Stainless Steel

2018 ◽  
Vol 941 ◽  
pp. 1784-1789
Author(s):  
Insup Lee
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Surface Hardness ◽  
Treatment Temperature ◽  
S Phase ◽  
Gas Content ◽  
Low Temperature Plasma ◽  
Temperature Plasma ◽  
Phase Layer ◽  
316L Austenitic Stainless Steel

The effect of gas content and treatment temperature on the surface characteristics of hardened layers of low temperature plasma nitrided 316L Austenitic Stainless Steel was investigated. The process was performed at fixed processing time at 15Hr and changing the N2content from 10% to 25%, changing the treatment temperature from 370 °C to 430 °C. The surface hardness and the thickness of expanded austenite (S-Phase) layer increase with increasing both temperature and nitrogen content. At 430°C processing temperature and 25% N2content, the S-phase layer thickness increased up to 13 μm and surface hardness increased about 3.5 times of that of untreated sample which is 880 HV0.1(before treatment 250HV0.1hardness). However, the XRD pattern of the this sample shows the presence of γ'-(Fe,Cr)4N precipitation on the surface which is the reason for the increased corrosion current density that results in increased corrosion rate. Thus the corrosion resistance degrades and presents even worst behavior comparing that of before treatment. Therefore, for increasing the corrosion behavior, further research was conducted by fixing the N2content at 10% with changing the CH4content from 0% to 5%. The best results were found when treated at 430°C with 5% CH4content. At this condition the S-phase thickness increase to around 17μm and surface hardness (980 HV0.1) is improved about 3.9 times of the hardness of untreated one. This sample also showed superior corrosion resistance than the other treated samples and the untreated one due to much higher pitting potential.

The Influence of Sandblasting and Electropolishing on the Surface Hardness of AISI 316L Stainless Steel

2014 ◽  
Vol 896 ◽  
pp. 517-520 ◽  
Author(s):  
Suyitno ◽  
Ishak
Keyword(s):  
Stainless Steel ◽  
Mass Fraction ◽  
Surface Hardness ◽  
Silica Sand ◽  
Maximum Output ◽  
Aisi 316L ◽  
Working Pressure ◽  
Dc Power ◽  
Steel Aisi ◽  
Stainless Steel Aisi

The purpose of this study is to analyze the effect of sandblasting and electropolishing on microstructure and hardness of stainless steel AISI 316L. The equipment used was sandblasting machine with a working pressure of 5-7 kg/cm2 with a duration of 10 minutes. The silica sand was used with size of 500-800 μm. The equipment used in the electropolishing process is the DC power supply with a maximum output of 2x100A. Anode and cathode material were stainless steel AISI 316L. Electrolyte solution consisted of 96% mass fraction of sulfuric acid and 85% mass fraction of phosphoric acid with a ratio of 1:1. The parameters used in the electropolish process were voltage of electrical, distance of electrodes and duration of electropolishing process. The results show that increasing the voltage, decreasing the distance, and increasing the duration of the electropolishing process increase the hardness up to 69%.

Failure analysis of AISI 316L ball valves by salt bath nitriding

2020 ◽  
Vol 111 ◽  
pp. 104455
Author(s):  
Guandong Luo ◽  
Zhi Zheng ◽  
Likui Ning ◽  
Zheng Tan ◽  
Jian Tong ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Salt Bath ◽  
Aisi 316L ◽  
Salt Bath Nitriding

Pitting Studies Under Anoxic Conditions on Candidate Container Materials AISI 316L hMo and UHB 904L for The Disposal of HLW in Argillaceous Formations

2003 ◽  
Vol 807 ◽  
Author(s):  
Bruno Kursten ◽  
Frank Druyts
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Near Field ◽  
Austenitic Stainless Steels ◽  
Aisi 316L ◽  
Progressive Change ◽  
Anoxic Conditions ◽  
The Impact ◽  
Container Material

ABSTRACTStainless steel is being envisaged as the primary candidate container material for the final disposal of vitrified HLW in deep geological argillaceous formations in Belgium. The impact of an evolving underground repository environment, i.e. a progressive change from oxic to anoxic conditions (due to the consumption of entrapped oxygen), on the pitting behaviour of austenitic stainless steels AISI 316L hMo and UHB 904L was studied. CPP-experiments were performed in synthetic solutions, which are representative for the near-field chemistry of an underground repository. The solutions contained various amounts of Cl- (100–50,000 mg/L) at near-neutral pH. Experiments were conducted at 16 and 90°C.AISI 316L hMo and UHB 904L will not be subjected to immediate pitting problems neither under oxic, nor under anoxic conditions. However, AISI 316L hMo could present long-term pitting problems under oxic conditions. Pits are much easier initiated on AISI 316L hMo, for both oxic and anoxic conditions. The pits propagate in a rather similar manner under oxic conditions for both alloys, whereas under anoxic conditions the pits formed on AISI 316L hMo are much deeper. AISI 316L hMo is more susceptible to crevice attack.

scholarly journals Dry Sliding Wear Behavior of AISI310 Stainless Steel with Low Temperature Salt Bath Nitriding and Gas Nitriding Processes

2019 ◽  
Vol 9 (1) ◽  
pp. 470-473
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Salt Bath ◽  
S Phase ◽  
Dry Sliding Wear ◽  
Wear Loss ◽  
Phase Layer ◽  
Gas Nitriding ◽  
Nitrided Sample ◽  
Minimum Wear

AISI 310 is an austenitic stainless steel that accomplished in high thermal applications like turbines, boiler parts etc. In this study AISI310 was treated with salt bath nit- -riding for 60min, 120min and 150min and gas nitriding for 6hrs, 12hrs and 18hrs at the temperature of 5700 c respectively. Comparison study of nitrided specimens were performed under various metallographic tests like scanning electron microscope, X-ray Diffraction, pin on disc apparatus. Experimental results shown that when salt bath nitrided sample at 150min showed a white layer called “S-phase” layer which was detected. In gas nitriding also “S-phase” layer, an expanded austenite was observed, after 18 hrs, CrN phase was discovered after the decomposition of s-phase layer gas nitrided sample of 18hrs which showed the best corrosion resistance .Salt bath specimen 150 min showed minimum wear loss and gas nitrided sample of 18hrs showed more hardness, minimum wear and improved corrosion resistance compared to untreated sample.

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