摘要:

Nitride capacities,, defined by (mass‐% N) ·in the CaO–SiO2and CaO–SiO2–AI2O3melts were measured in the temperature range of 1 723 to 1 923 K by a gas‐slag equilibration technique using CaO, Al2O3, and Mo crucibles. Nitrogen content in slag, (mass‐% N), was proportional to oxygen partial pressure,, to the power of −3/4 at constant nitrogen partial pressure,. The values forincreased linearly with increasing temperature and increased with the content of nitride formers, SiO2and Al2O3, but the effect of SiO2onvalue was found to be greater than that of Al2O3. The activity coefficients of Si3/4N in the CaO–SiO2melts tended to increase with increasing the content of SiO2.

ISSN:0003-8962    

DOI:10.1002/srin.199200459

出版商:Wiley    

年代:2016

数据来源: WILEY

ISSN:0003-8962    

DOI:10.1002/srin.199200460

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

After a former detailed study of the thin strip casting process now defects of the strip and their avoidance are discussed. Hence it is deduced that the casting process should be carried out with small rolling forces. Thus the process of strip cooling has to be separated from the process of strip forming, and a cooling device has to be established close to the casting rolls.

ISSN:0003-8962    

DOI:10.1002/srin.199200461

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

A theoretical model for the concomitant solidification of droplets and preform during spray deposition has been proposed, based on heat‐flow analysis. It has been unambiguously demonstrated that cooling rates approaching those in the rapid solidification (RS) regime can only be achieved when the droplets are still in free flight during the deposition process. The cooling rates in the droplets range from 104–106Ks−1depending upon their size for the experimental conditions employed in the present studies. In contrast, the model predicted cooling rates for the deposits in the region of 103–104Ks−1. A hypoeutectic Fe‐3C‐1.5Mn‐0.3Si has been chosen as an experimental alloy for studies relating to microstructural characterization. The microstructure of powder developed fully during solidification of droplets in free flight revealed dendritic morphology of the metastable austenitic phase, whereas the spray‐deposited alloy exhibited characteristic homogeneous and refined substructure. The evolution of microstructure during spray deposition as also during atomization has been compared and discussed by invoking the proposed model.

ISSN:0003-8962    

DOI:10.1002/srin.199200462

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

The present study is concerned with the design of mist nozzle to produce air/water mist jet, and to investigate the behaviour of mist jet and its capacity to cool the hot steel surface. The behaviour of the mist jet is studied by collecting water at different axial distances. Radial water flux profile is correlated with a Gaussian type of distribution function under a wide range of experimental conditions. Maximum water flux in the mist jet is correlated with the downstream axial distance and water‐loading ratio. Water‐loading ratio is found to influence water flux more strongly than axial distance. Radius of the mist jet is correlated with the downstream distance. It is found that the mist jet cools a crack‐sensitive steel without Cracking and, at the same time, produces a martensite type of structure.

ISSN:0003-8962    

DOI:10.1002/srin.199200463

出版商:Wiley    

年代:2016

数据来源: WILEY

ISSN:0003-8962    

DOI:10.1002/srin.199200464

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

In dieser Arbeit wird die Notwendigkeit eines weiterentwickelten Zweiflächenverfestigungsmodells auf der Grundlage des Übergangsfließpotentials für zyklische Plastizität am Beispiel der metallischen Werkstoffe AIMgSi1 und X 2 CrNi 18.9 dargelegt. Die Auswertung der experimentellen Ergebnisse zeigt eine ausgeprägte Entwicklung der Fließflächengeometrie, ferner der isotropen und der kinematischen Verfestigung.

ISSN:0003-8962    

DOI:10.1002/srin.199200465

出版商:Wiley    

年代:2016

数据来源: WILEY

ISSN:0003-8962    

DOI:10.1002/srin.199200466

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

The isothermal transformation products of austenite over a wide range of temperatures and times in the bainitic range in a 0.2 wt.% C–1.5 wt.% Mn steel have been studied by transmission electron microscopy in order to characterise the bainitic microstructures in low‐carbon low‐alloy steels. Widmanstätten ferrite has formed with alternate layers of austenite (martensite) as a transition product at 600 and 500°C that has finally transformed on further isothermal transformation to either pearlite (at 600°C) or upper bainite (at 500°C). This type of transformation product was referred to as BI bainite by earlier investigators, but on the basis of the present investigation it is concluded that such ferrite‐austenite (martensite) structures are not bainitic as this is not the final transformation product either at 600 or 500°C. Both upper bainite and lath‐type lower bainite are formed at 450°C while the transformation product has been only lath‐type lower bainite at 400°C.

ISSN:0003-8962    

DOI:10.1002/srin.199200467

出版商:Wiley    

年代:2016

数据来源: WILEY

摘要:

Characteristic differences between the interrupted and the uninterrupted creep‐rupture test are shown. Possible reasons for different test results are analysed. Specially designed comparison tests indicate that the results based on the different test methods remain within an expected scatterband dictated by inaccuracies of the testing techniques.

ISSN:0003-8962    

DOI:10.1002/srin.199200468

出版商:Wiley    

年代:2016

数据来源: WILEY