The Role of Nano-TiO2 Lubricating Fluid on the Hot Rolled Surface and Metallographic Structure of SS41 Steel

In order to investigate the susceptibility of steels to hydrogen embrittlement as a function of their microstructure X70 steel was chosen in different conditions: normalized transfer bar, as-received hot rolled strip and heat affected zone (HAZ). Notched and fatigue pre-cracked samples were subjected to electrochemical hydrogen charging to achieve 2 ppm hydrogen content. Three point bend tests were conducted on as-received and hydrogen charged samples. The results showed that HAZ samples are more susceptible to hydrogen embrittlement than the others. This was supported by fracture surface observations.

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Role of microalloyed Sm in enhancing the corrosion resistance of hot-rolled Mg–8Sn–1Al–1Zn alloy

Corrosion Science ◽

10.1016/j.corsci.2021.109425 ◽

2021 ◽

pp. 109425

Author(s):

Jaeho Kwon ◽

Soo-Min Baek ◽

Hoseok Jung ◽

Jong Chan Kim ◽

Si-Young Lee ◽

...

Keyword(s):

Corrosion Resistance ◽

Hot Rolled

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The Effect of Alloying Elements on the Stability of Centerline Segregation

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.297-301.148 ◽

2010 ◽

Vol 297-301 ◽

pp. 148-153 ◽

Cited By ~ 1

Author(s):

Mihály Réger ◽

Balázs Verő ◽

Ibolya Kardos ◽

Péter Varga

Keyword(s):

Carbon Activity ◽

Middle Part ◽

Steel Plates ◽

Alloying Elements ◽

Centerline Segregation ◽

Quality Properties ◽

Continuously Cast ◽

The Stability ◽

Hot Rolled

The paper deals with the stability of centerline inhomogenity of continuously cast slabs and hot rolled products. The centerline segregation is a disadvantageous failure of slabs which can affect the quality properties of the final products. During hot rolling of slabs the centerline segregation pattern will become thin and stretch and it can also be detected in the middle part of heavy plates and coils. It is a common experience that the centerline segregation of heavy plates can not be easily decreased by post heat treatment. The pattern of the centerline segregation was modeled physically by preparing a sandwich structure of steel plates with different levels of carbon and alloying elements. Homogenization experiments were performed and the samples were examined metallographically. Diffusional calculations proved the governing role of carbon activity which is influenced by the distribution of alloying elements.

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HIGH AC VOLTAGE FLOW-MODIFIED PERMITTIVITY AND RHEOLOGICAL PROPERTIES OF CARBON-DOPED NANO TiO2 ER FLUIDS

International Journal of Modern Physics B ◽

10.1142/s0217979201005076 ◽

2001 ◽

Vol 15 (06n07) ◽

pp. 618-625 ◽

Cited By ~ 3

Author(s):

Z. Y. QIU ◽

F. K. SHAN ◽

L. W. ZHOU ◽

F. LU ◽

Y. H. ZHU

Keyword(s):

Field Strength ◽

Rheological Properties ◽

Carbonization Temperature ◽

Exciting Field ◽

Nano Tio2 ◽

Carbon Doped ◽

Shear Rates ◽

Er Fluids ◽

Particle Orientations

The associated effects of polarization strength, polarization rate, and dielectric loss on ER performance ware studied by means of the correlation of rheological properties of carbon-doped TiO 2 ER fluids with experimental results of flow-modified permittivity (FMP). We prepared ER fluids with carbon-doped TiO 2 powders of different conductivity via controlling carbonization temperature and organic contents. The experiments present the optimum organic contents of 4.6% to 9.2% and the optimum carbonization temperature of around 673 K for the better ER activity. The role of conductivity in ER performance is testified. FMP measurements of fluids were performed under weak and strong exciting fields respectively. Under weak exciting field, FMP effects are hardly detectable; while under high exciting field, FMP effects become significant which reflect ER particle configurations, particle orientations, and limited dielectric response time in the combined electric and shear fields. The shear field strength, exciting field strength and frequency are the three main factors influencing the FMP effects. The FMP data can be modeled and qualitatively explained by introducing two characteristic shear rates of D c 1 and D c 2, J = J 0+ J 1 exp (- D / D c 1)+ J 2 exp (- D / D c 2) with D being shear rate.

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Defect clusters of molybdenum alloys bombarded by HVEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010915x ◽

1978 ◽

Vol 36 (1) ◽

pp. 402-403

Author(s):

N. Igata ◽

A. Kohyama ◽

H. Murakami ◽

K. Itadani ◽

H. Tsunakawa

Keyword(s):

Incident Beam ◽

In Situ Observation ◽

Dislocation Loops ◽

Defect Clusters ◽

Voltage Electron ◽

Molybdenum Alloys ◽

Damage Process ◽

Hot Rolled

As a simulation study of heavy radiation damage by neutrons, in-situ observation of damage process in molybdenum alloys was performed by a high voltage electron microscope. The objectives of this study are to clarify the processes of defect cluster nucleation and growth, and the role of alloying elements on these in the temperature range from 300K to 1300K.The used molybdenum alloys were Mo-(150-1000)at.ppm.C, Mo-(0.06-0.6)at.%Nb, MO-0.29at.%Hf, MO-(0.026-26)at.%Re and Mo-0.56at.%Ni. The used materials were electron-beam melted and hot rolled at 200-400°C and annealing was performed in the vacuum of l×l0-7torr. at 1800°C for 1.0 hr. The standard irradiation conditions were as follows,Accelerating voltage: 1250KV, Beam intensity: l-6×l019 e/cm2 sec, Incident beam direction: <100>, g-vector: {110},The density of defect clusters was determined by the thickness gradient method.The logarithmic density of interstitial dislocation loops, logNi, increased with the reciprocal irradiation temperature, 1/T. The relation between logNiand 1/T was divided into two Arrhenius type relations above and below 500K.

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