Enhancing Surface Properties of Fine Grain Duplex Stainless Steel via Superplastic Carburizing

2006 ◽  
Vol 15-17 ◽  
pp. 768-773 ◽  
Author(s):  
Nik Rozlin Nik Masdek ◽  
Iswadi Jauhari ◽  
Hiroyuki Ogiyama ◽  
Rafidah Hasan
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Surface Properties ◽  
Surface Hardness ◽  
Carbon Diffusion ◽  
Carbon Layer ◽  
Case Depth ◽  
Fine Grain ◽  
New Type ◽  
Kinetics Of

In this research, a new type of surface carburizing method which combines superplastic phenomenon and carburizing process called superplastic carburizing (SPC) was introduced. Thermo-mechanically treated duplex stainless steel (DSS) with fine grain microstructure and exhibits superplasticity was used as the superplastic material. The SPC was conducted at temperatures ranging from 1123 K to 1223 K for various durations. Initial loads of 25 MPa, 49 MPa and 74 MPa were applied to give the superplastic deformation effect on the carburized specimens. Metallographic studies revealed a thick, uniform, smooth and dense morphology of hard carbon layer formed at the surface of fine grain DSS. The resulting case depth of carbon layers were between 15 μm to 76 μm. A remarkable increase in surface hardness was observed in the range of 600 HV to 1600 HV. The kinetics of this process in terms of carbon diffusion and its variation with processing time and temperature was achieved using Arrhenius equation. Activation energy (Q) was determined as 151.87 kJ/mol. Based on the results obtained, SPC process can significantly enhance the surface properties of DSS.

A Study on Properties and Kinetics of Carburizing Superplastic Duplex Stainless Steel

2006 ◽  
Vol 326-328 ◽  
pp. 1677-1680 ◽  
Author(s):  
Nik Rozlin Nik Masdek ◽  
Iswadi Jauhari ◽  
Raden Dadan Ramdan ◽  
Rafidah Hasan
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Carbon Diffusion ◽  
Carbon Layer ◽  
Case Depth ◽  
Hard Carbon ◽  
Metallographic Technique ◽  
New Type ◽  
Kinetics Of ◽  
Carburizing Process

In this study, a new type of surface carburizing process was introduced using superplastic duplex stainless steel (DSS). The superplastic DSS was carburized at temperatures ranging from 1123 K to 1223 K for various durations. Initial pressures of 25 MPa, 49 MPa and 74 MPa were applied to give the superplastic deformation effect on the carburized specimens. SEM studies revealed a thick, uniform, smooth and dense hard carbon layer was formed on the surface of the superplastic DSS. By using metallographic technique and SEM, the resulting case depth of carbon layer was between 15 /m to 76 /m. The kinetics of this process in terms of carbon diffusion and its variation with processing time and temperature was determined using Arrhenius equation. Activation energy (Q) was determined as 152 kJ/mol.

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.

Effects of Superplasticity in Boronizing of Duplex Stainless Steel

2006 ◽  
Vol 326-328 ◽  
pp. 1233-1236 ◽  
Author(s):  
Rafidah Hasan ◽  
Iswadi Jauhari ◽  
Hiroyuki Ogiyama ◽  
Raden Dadan Ramdan
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Surface Hardness ◽  
Load Condition ◽  
Boride Layer ◽  
Coarse Grain ◽  
Superplastic Behavior ◽  
Compression Load ◽  
Fine Grain ◽  
Hardness Values

In this research, conventional boronizing process (CB) and a new method of boronizing process under compression load condition (LB) were conducted and compared in order to study the effect of superplasticity on boronized substrate. Both processes were conducted on duplex stainless steel (DSS) with two different microstructures; as-received DSS with coarse grain microstructure (CDSS); and thermo-mechanically treated DSS with fine grain microstructure (FDSS) which can show superplastic behavior at high temperatures. Both processes were conducted at duration of 6 hours and temperatures between 1123 and 1223 K. All of boronized specimens demonstrated thin, smooth and compact morphology of boride layer. For CDSS, both CB and LB processes produced about similar surface hardness values within the range of 1425 – 2330 HV. For FDSS, CB process produced surface hardness between 1522 and 2601 HV, while under LB, the highest surface hardness values in the range of 1659 - 2914 HV were obtained. The result shows that introduction of load during boronizing has initiated superplastic deformation on FDSS thus accelerated diffusion of boron atoms into surface which finally lead to significantly higher surface hardness.

scholarly journals Effect of Low-Temperature Plasma Nitriding on Corrosion and Surface Properties of Duplex Stainless Steel UNS S32205

2020 ◽  
Vol 29 (4) ◽  
pp. 2612-2622
Author(s):  
Yamid E. Núñez de la Rosa ◽  
Oriana Palma Calabokis ◽  
Paulo César Borges ◽  
Vladimir Ballesteros Ballesteros
Keyword(s):  
Stainless Steel ◽  
Low Temperature ◽  
Duplex Stainless Steel ◽  
Surface Properties ◽  
Plasma Nitriding ◽  
Low Temperature Plasma ◽  
Temperature Plasma

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.

Kinetics of carburizing of duplex stainless steel (DSS) by superplastic compression at different strain rates

2010 ◽  
Vol 527 (16-17) ◽  
pp. 4257-4261 ◽  
Author(s):  
Nor Wahida Ahamad ◽  
Iswadi Jauhari ◽  
Sharidah Azuar Abdul Azis ◽  
Nur Hafizah Abd Aziz
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Strain Rates ◽  
Kinetics Of

scholarly journals Study on Upgradation in Carburizing Technologies for steel strength

2019 ◽  
pp. 78-84
Keyword(s):  
Surface Hardness ◽  
Carbon Diffusion ◽  
Lower Surface ◽  
Diffusion Controlled ◽  
Steel Strength ◽  
Carbon Transfer ◽  
Gas Carburizing ◽  
Kinetics Of ◽  
Plasma Carburizing ◽  
Carburizing Process

Carburizing technologies are used to provide strength on low quality metals. This technology is being developing with novel improvements significantly. The carburizing process consists of, first releasing Carbon mono-oxide from charcoal material and then transfers carbon to raw metal. There are favorable upgradation in these technologies from researchers which have a paramount industrial importance. In Vacuum gas carburizing, the steel metal is carburized with (Acetylene and Propane) gases. These gases are at low pressure and high temperature. The results show that the metal is 1.5 times harder than its raw form. There are also used mathematical models to validate the results. It used gas and solid phases for validation. In pulse carburizing, carbon diffusion on steel is investigated with heat treatment. This process includes several carburizing stages. This process is based on Darken bi velocity and drift velocity. It accounts to demonstrate the kinetics of carbon transfer on steel surface. This design is very useful by regarding carburizing time for this process design. In Plasma carburizing, the mixtures of gases are used to harden the steel. The carburizing temperature was varied in cementite and martensitic. The favorable results show that these specimens have (Lower surface roughness, higher surface hardness and Low wear rate). It is a most novel diffusion controlled novel process till the present time. The carburized metal is used in industry by including (Turbine gears and Air craft engine). Henceforth, It is of great importance to study the carburizing technologies for providing better strength on metal.

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