1. |
Control of the chromium‐oxygen reaction in pure iron melts |
|
Archiv für das Eisenhüttenwesen,
Volume 66,
Issue 2,
2016,
Page 39-44
Stefan Dimitrov,
Heike Wenz,
Klaus Koch,
Dieter Janke,
Preview
|
PDF (492KB)
|
|
摘要:
Oxygen activities in Fe‐O‐Cr melts, equilibrated with chromium oxide, were determined as a function of chromium content by EMF measurements using ZrO2(CaO) plug‐type sensors with a Cr‐Cr2O3reference. Plug‐type sensors with or without Cr2O3saturator were used in the experiments. From the experimental results values for the activity coefficientfOand the interaction parametersandwere evaluated. Raoultian chromium activity features a slight positive deviation from ideal solution behaviour in the temperature range from 1550 to 1650°C. Taking into account the calculated interaction parameters, the equilibrium constantKCr‐Owas redetermined at 1550 to 1650°C. In comparison with previous studies a better agreement was obtained with existing thermochemical data.
ISSN:0003-8962
DOI:10.1002/srin.199501085
出版商:Wiley
年代:2016
数据来源: WILEY
|
2. |
The effect of specimen geometry on the accuracy of the constitutive equation derived from the hot torsion test |
|
Archiv für das Eisenhüttenwesen,
Volume 66,
Issue 2,
2016,
Page 45-49
Shahin Khoddam,
Y. C. Lam,
P. F. Thomson,
Preview
|
PDF (416KB)
|
|
摘要:
A rigid‐viscoplastic FE code has been used to simulate the isothermal hot torsion of specimens used in tests designed for determining the relationship governing constitutive behaviour. For a given constitutive equation, the torque‐rotation data were derived from the FE analysis of specimens of various geometries. Subsequently, based on these data, the constitutive equation was regenerated using an existing analytical relationship relating torque and twist in a cylindrical specimen. The effect of geometry of hot torsion specimens on the accuracy of the constitutive equation derived from the analytical relationship was investigated. Recommendations on the preferred geometry of hot torsion specimens for high deformations were made.
ISSN:0003-8962
DOI:10.1002/srin.199501086
出版商:Wiley
年代:2016
数据来源: WILEY
|
3. |
Calculation of the temperature distribution in dieless drawing |
|
Archiv für das Eisenhüttenwesen,
Volume 66,
Issue 2,
2016,
Page 50-54
Oskar Pawelski,
Alfons Kolling,
Preview
|
PDF (542KB)
|
|
摘要:
Dieless drawing is an example of flexible metal forming processes. The investigation of the main process parameters and their interdependence is the prerequisite for the deliberate choice of input parameters to get the desired quality of the workpiece. Drawing force, drawing velocity, and temperature are the main control parameters. But only the temperature can be influenced locally whereas the force and the velocity can be adjusted only globally. Because of this special importance of the temperature analytical and numerical models for the temperature distribution along the deformation zone have been developed.
ISSN:0003-8962
DOI:10.1002/srin.199501087
出版商:Wiley
年代:2016
数据来源: WILEY
|
4. |
Improving the quality of high and low‐carbon steel rods employed in wire drawing operations |
|
Archiv für das Eisenhüttenwesen,
Volume 66,
Issue 2,
2016,
Page 55-62
Rodolfo Morales Dávila,
David Jaramillo Vigueras,
Miguel Toledo Velázques,
Preview
|
PDF (694KB)
|
|
摘要:
High and low tensile strength as well as high ductility are required for both, high and low‐carbon steel rods which are to be further processed in wire drawing operations. In addition to chemical composition, suitable cooling rates are important for the control of mechanical properties, as far as the Stelmor process is concerned. In this investigation, heat transfer models are coupled with the kinetics of austenite transformation into pearlite and ferrite‐pearlite, respectively, in order to understand the link between the Stelmor process parameters and the final quality of low and high‐carbon steel rods.In applying these models a considerable difference occurred in the mechanical properties of high‐carbon rod samples taken from the loop edge of the Stelmor conveyor and those taken from the loop center. The latter showed higher tensile strengths, furthermore, the difference to the lower‐strength samples increased with low conveyor speeds. Most homogeneous mechanical properties were found for a conveyor speed of 0.4 m/s. In the case of low‐carbon steels, low nitrogen contents during steelmaking and a slow and controlled cooling in the Stelmor process were found to be the most important factors regarding mechanical properties. The conclusions of this investigations are actually being applied to production so as to obtain a better quality of steel rod semies.
ISSN:0003-8962
DOI:10.1002/srin.199501088
出版商:Wiley
年代:2016
数据来源: WILEY
|
5. |
On the crack susceptibility of high alloyed tool steels during continuous casting and in the temperature region of hot working |
|
Archiv für das Eisenhüttenwesen,
Volume 66,
Issue 2,
2016,
Page 63-71
Ralf Thome,
Winfried Dahl,
Preview
|
PDF (1284KB)
|
|
摘要:
Hot tensile tests after applied prior melting down of the specimens were carried out on mainly ledeburitic tool steels and their strength and ductility were determined in the temperature range between liquidus and 900°C. The test parameters and specimen microstructures were adapted to the conditions and structures prevailing in continuous casting and primary hot working of blooms. The metallurgical processes leading to the embrittlement of the material were examined by means of metallographic investigations. The temperature ranges of internal crack susceptibility and low ductility were evaluated.
ISSN:0003-8962
DOI:10.1002/srin.199501089
出版商:Wiley
年代:2016
数据来源: WILEY
|
6. |
The influence of aluminium deoxidation and sulphur content on oxide modification and machinability of steel |
|
Archiv für das Eisenhüttenwesen,
Volume 66,
Issue 2,
2016,
Page 72-76
Zhou Hong,
Xiaochun Wu,
Cui Kun,
Preview
|
PDF (457KB)
|
|
摘要:
The influence of Al‐deoxidation and various amounts of sulphur on Ca‐treated steel has been investigated. The effect of sulphur ar aluminium on the modification of oxide inclusions has been reasoned by theoretical thermodynamic equilibrium analysis. The type inclusion formed depends on the aluminium and sulphur contents. For complete oxide shape control in which CaO‐rich inclusions forr the sulphur content must be relatively low for Al‐killed steel. The oxide inclusion type of the experiments was in surprisingly goc agreement with the prediction of thermodynamics. The influence of calcium and sulphur on the machinability and mechanical properties has also been demonstrated as well as the improvement of isotropy in steel obtained by Ca‐addition.
ISSN:0003-8962
DOI:10.1002/srin.199501090
出版商:Wiley
年代:2016
数据来源: WILEY
|
7. |
News from the Max‐Planck‐Institut für Eisenforschung GmbH |
|
Archiv für das Eisenhüttenwesen,
Volume 66,
Issue 2,
2016,
Page 77-86
Preview
|
PDF (1162KB)
|
|
ISSN:0003-8962
DOI:10.1002/srin.199501091
出版商:Wiley
年代:2016
数据来源: WILEY
|