1. |
Application of thermodynamic computations to the solution behaviour of niobium and vanadium carbonitrides |
|
Archiv für das Eisenhüttenwesen,
Volume 64,
Issue 3,
2016,
Page 143-147
Hans‐Joachim Eckstein,
Mario Fennert,
Joachim Ohser,
Preview
|
PDF (450KB)
|
|
摘要:
On the basis of well‐known thermodynamic equations, a model is proposed which allows the computation of both the solution behaviour and the composition of the carbonitride precipitates of the microalloying elements in steel. Apart from the concentration of the microalloying elements and the carbon and nitrogen content, the following aspects were taken into account: the non‐stoichiometric composition of carbonitrides, a regular solution behaviour of the mixture of carbide with nitride, the effect of third elements on the activity of carbon and nitrogen, the possible primary binding of nitrogen by aluminium. The calculation is based on the knowledge of the solubility products of pure carbides and nitrides. Comparison with experimental results of carbonitride precipitates in microalloyed niobium and vanadium steels support the model‐based predictions concerning the temperature‐dependent composition and solubility of carbonitrides under equilibrium conditions.
ISSN:0003-8962
DOI:10.1002/srin.199300999
出版商:Wiley
年代:2016
数据来源: WILEY
|
2. |
Thermodynamic behaviour of phosphorus in Mn‐Si‐Ca‐P melts |
|
Archiv für das Eisenhüttenwesen,
Volume 64,
Issue 3,
2016,
Page 148-152
Zhongting Ma,
Ruiming Ni,
Wu Cheng,
Shoukun Wei,
Preview
|
PDF (405KB)
|
|
摘要:
Thermodynamic experiments of Mn‐Si‐Ca‐P melts were carried out in Mo‐wire‐heated furnace. With these experimental data, the first and second order activity interaction coefficients of Ca, Si and P upon P under the conditions of the same activity and the same concentration method were evaluated. The standard free energy of solution of P in liquid Mn based on 1 wt.% solution standard formulated in temperature was given and it only holds near 1623 K.
ISSN:0003-8962
DOI:10.1002/srin.199301000
出版商:Wiley
年代:2016
数据来源: WILEY
|
3. |
Application results of Al2O3porous plug containing TiO2, Al2O3and MgO as matrixes on an actual operation |
|
Archiv für das Eisenhüttenwesen,
Volume 64,
Issue 3,
2016,
Page 153-156
Akihiro Tsuchinari,
Toshiyuki Hokii,
Atsushi Eba,
Hiroyuki Imai,
Chikao Kanaoka,
Preview
|
PDF (570KB)
|
|
摘要:
Al2O3porous plugs containing TiO2, Al2O3and MgO in the matrix were applied for 200‐t ladle (improved porous plug). Although cracks occurred in longitudinal and transverse direction in the conventional porous plugs, no cracks were observed in the improved porous plug. Therefore, the latter was superior to the conventional one in thermal shock resistance. Wear rate was 9.0 mm/heat for improved plug and 9.8 mm/heat for the conventional one in average. The improved plug showed higher corrosion resistance than the conventional one. With the improved porous plug O2cleaning was only necessary after every two heats. This was due to the high penetration resistance.
ISSN:0003-8962
DOI:10.1002/srin.199301001
出版商:Wiley
年代:2016
数据来源: WILEY
|
4. |
Influence of running water on the heat transfer in continuous casting |
|
Archiv für das Eisenhüttenwesen,
Volume 64,
Issue 3,
2016,
Page 157-164
Viktor Heidt,
Rudolf Jeschar,
Preview
|
PDF (812KB)
|
|
摘要:
The influence of running water on spray water cooling is experimentally looked at with the aid of a stationary working experimental plant. The running water was fed separately to the sample from above as a defined water film by using a slot nozzle. In addition to the spray nozzle pre‐pressure, the velocity of the running water at the slot nozzle exit and the temperature of the running water, the angle of inclination of the sample plane was also varied. By employing three different full cone spray nozzles and setting different nozzle distances, a range of 450 to 2000 l/(m2·min) of the water impingement density was covered. To estimate the marginal influences, samples of 20 × 20 mm as well as 30 × 30 mm were used. Studies of initially pure spray water cooling without the additional running water film revealed a dependency of the heat transfer on the spray water impingement density, the spray water velocity and also the angle of inclination of the sample plane. For nozzles with a low water impingement density, a superimposing of a running water film on the spray water revealed a sharp increase in the heat transfer coefficients compared to pure spray water cooling. For nozzles with a high water impingement density and, therefore, with a high heat transfer already even for pure spray water cooling, the increase of the heat transfer coefficient is minor.
ISSN:0003-8962
DOI:10.1002/srin.199301002
出版商:Wiley
年代:2016
数据来源: WILEY
|
5. |
Alloying steel with nitrogen from gas phase in high‐pressure plasma reactor |
|
Archiv für das Eisenhüttenwesen,
Volume 64,
Issue 3,
2016,
Page 165-170
Stanislaw Tochowicz,
Jerzy Siwka,
Jan Jowsa,
Preview
|
PDF (537KB)
|
|
摘要:
The paper presents a study of the possibility of saturating austenitic Cr18%–Mn18% steel with nitrogen from the gas phase by use of “low – temperature” thermal plasma. The experimental work was carried out in a DC plasma reactor of the authors' own design working at a total gas pressure of 0.38 MPa on a 20 kg sample. It was evident that it was possible to obtain a very high level of nitrogen saturation close to the level of nitrogen solubility in the metal by the use of plasmogenic gas containing purified nitrogen. The highest content of nitrogen in steel containing 18wt.% chromium and 16.7wt.% manganese was 0.77wt.% at [C] = 0.054. Refining the metal with CaSi additive turned out to have a stabilizing influence, the total amount of oxygen and sulphur being lower than 200 ppm. The material obtained turned out to be also highly homogeneous chemically after solidification.
ISSN:0003-8962
DOI:10.1002/srin.199301003
出版商:Wiley
年代:2016
数据来源: WILEY
|
6. |
Tempering characteristics of a Cr‐Mo dual phase steel |
|
Archiv für das Eisenhüttenwesen,
Volume 64,
Issue 3,
2016,
Page 171-177
Bimal K. Jha,
Ram Avtar,
V. Sagar Dwivedi,
Nirmalendu S. Mishra,
Preview
|
PDF (1100KB)
|
|
摘要:
Full potential of dual phase steels in as‐hot rolled condition is not being realized at present because of certain difficulties associated with coiling as well as welding. Autotempering of martensite may lead to anomalous properties at different locations in the coil. An industrially as‐hot rolled Cr‐Mo dual phase steel has been chosen to study its tempering behaviour. The response to tempering by varying temperatures for a fixed time interval of one hour has been monitored through evolution in microstructure, as revealed by transmission electron and light microscopy on the one hand, and measurement of mechanical properties on the other. An attempt has been made to establish structure‐property correlation for different tempering treatments. Two temperature regimes have been identified: the one below 300°C, wherein no significant change in microstructure occurs while the other above 300°C is marked by the precipitation of ∊‐carbide and its subsequent dissolution to give way to the formation of cementite. The observed maximum in the yield stress at ∼300°C is linked with the precipitation of ∊‐carbide. The onset of softening thereafter has been shown to be due to the formation of subcells in ferritic regions and recovery taking place in the martensitic phase together with globularization of cementite. The ductility minimum has been observed at ∼400°C and this has been attributed to the segregation of impurities to the grain boundaries.
ISSN:0003-8962
DOI:10.1002/srin.199301004
出版商:Wiley
年代:2016
数据来源: WILEY
|
7. |
On the stability of retained austenite and its role in improvement of the cryogenic toughness for Ni9 steel |
|
Archiv für das Eisenhüttenwesen,
Volume 64,
Issue 3,
2016,
Page 178-182
Futian Zhang,
Man Hu,
Zhifei Lou,
Preview
|
PDF (770KB)
|
|
摘要:
The relationship between the mechanical stability of retained austenite(γ') and the cryogenic toughness of Ni9 steel has been investigated and the phenomena of γ' → martensite(α') transformation in the process of impact deformation‐fracture have been observed. The results show that the role of γ'‐phase itself is beneficial to cryogenic toughness but rather small, the main reason of good cryogenic toughness in large margin is perhaps γ' → α' transformation performed in process of the impact‐fracture.
ISSN:0003-8962
DOI:10.1002/srin.199301005
出版商:Wiley
年代:2016
数据来源: WILEY
|