Obtaining Ultrafine and Nanocrystalline Structure by Hot and Warm Deformation in Microalloyed Steel X90

2012 ◽  
Vol 706-709 ◽  
pp. 1624-1629 ◽  
Author(s):  
Dmitry Ringinen ◽  
Nicolay G. Kolbasnikov ◽  
Oleg G. Zotov ◽  
Andrey Rudskoy
Keyword(s):  
Mechanical Properties ◽  
Microalloyed Steel ◽  
Nanocrystalline Structure ◽  
High Strength ◽  
Controlled Rolling ◽  
Bainite Transformation ◽  
Warm Deformation ◽  
Processing Mode ◽  
Steel Strength ◽  
Different Temperatures

In this paper we have investigated the possibility of increasing the complex mechanical properties of steel strength category X90 by refinement the structure of hot and warm deformation. Were carried out tests to determine the critical points of recrystallization and built thermokinetic curves of austenite decomposition. After that, for produce disperse ferrite in samples has been applied to the processing mode, which is exactly the same mode of controlled rolling, then, to obtain nanoscale state of the metal deformed at temperatures of bainite transformation with varying degrees of deformation at different temperatures. It was shown that the dispersion and morphology of the structure and, consequently, the mechanical properties vary depending on temperature and strain, and samples show satisfactory ductility at high strength.

Consolidation and Mechanical Properties of Mechanically Alloyed Al-Mg Powders

2008 ◽  
Vol 1128 ◽  
Author(s):  
Mira Sakaliyska ◽  
Sergio Scudino ◽  
Hoang Viet Nguyen ◽  
Kumar Babu Surreddi ◽  
Birgit Bartusch ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Nanocrystalline Structure ◽  
Hot Extrusion ◽  
High Strength ◽  
Processing Route ◽  
Compression Tests ◽  
Mechanically Alloyed ◽  
Different Temperatures ◽  
Microstructure Density

AbstractNanostructured Al-Mg bulk samples with compositions in the range of 10 – 40 at.% Mg have been produced by consolidation of mechanical alloyed powders. Powders with composition Al90Mg10 and Al80Mg20 were consolidated into highly dense specimens by hot extrusion. Room temperature compression tests for the Al90Mg10 specimen reveal interesting mechanical properties, namely, a high strength of 630 MPa combined with a plastic strain of about 4 %. The increase of the Mg content to 20 at.% increases the strength by about 100 MPa but it suppresses plastic deformation. The Al60Mg40 powder was consolidated at different temperatures by spark plasma sintering and the effect of the sintering temperature on microstructure, density and hardness have been studied. The results reveal that both density and hardness of the consolidated samples increase with increasing sintering temperature, while retaining a nanocrystalline structure. These results indicate that powder metallurgy is a suitable processing route for the production of nanocrystalline Al-Mg alloys with promising mechanical properties.

Spun Steel Pipes for the Offshore Industry

1983 ◽  
Vol 105 (1) ◽  
pp. 97-102 ◽  
Author(s):  
A. Royer ◽  
B. Dumas ◽  
M. Gantois
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Centrifugal Casting ◽  
High Strength ◽  
Controlled Rolling ◽  
Climatic Conditions ◽  
Casting Technique ◽  
Steel Pipes ◽  
Potential Applications ◽  
Offshore Industry

Many parts either for sea-line pipes as “buckle” or “crack arrestor,” or for structures may require the use of wall tubular products with high mechanical properties. Such heavy-wall pipes may be produced by centrifugal casting. Two Mn-Mo steels have been developed for medium-wall pipes (e≤35 mm) to be used under very severe climatic conditions: an acicular ferritic steel, a pearlite reduced steel produced by controlled rolling techniques [1, 2, 3]. More alloyed chemical composition and heat-treatments are needed to produce heavy-wall pipes. Then, production of such pipes is more difficult and sometimes impossible. Observations made on controlled-rolled Mn-Mo steel led to a better understanding of the influence of metallurgical structures and chemical composition on steel characteristics. Similar metallurgical structures can only be reached via other routes, for example centrifugal-casting of steel associated with heat-treatment, lead to the production of heavy-wall pipes with high strength and suitable transition temperature. After a brief description of the centrifugal casting technique, we introduce the grades developed for heavy-wall pipes with yield strength up to 100,000 psi. The mechanical properties, Battelle, fatigue, static bending, C.O.D., weldability, etc., of Centrishore II are given and compared to other materials. Possible offshore applications and other potential applications of parts produced by centrifugal casting are described.

The Influence of Thermomechanical Controlled Processing on Bainite Formation in Low Carbon High Strength Steel

2014 ◽  
Vol 783-786 ◽  
pp. 21-26
Author(s):  
Xiao Jun Liang ◽  
Ming Jian Hua ◽  
Anthony J. DeArdo
Keyword(s):  
Mechanical Properties ◽  
High Strength Steel ◽  
High Strength ◽  
Manganese Steel ◽  
Low Carbon ◽  
High Manganese ◽  
Bainite Transformation ◽  
High Manganese Steel ◽  
Cooling Rates ◽  
Controlled Processing

Thermomechanical controlled processing is a very important way to control the microstructure and mechanical properties in low carbon, high strength steel. This is especially true in the case of bainite formation, where the complexity of the austenite-bainite transformation makes the control of the processing important. In this study, a low carbon, high manganese steel containing niobium was investigated to better understand the roles of austenite conditioning and cooling rates on the bainitic phase transformation. Specimens were compared with and without deformation, and followed by seven different cooling rates ranging between 0.5°C/s and 40°C/s. The CCT curves showed that the transformation behaviors and temperatures are very different. The different bainitic microstructures which varied with austenite deformation and cooling rates will be discussed.

Effect of Finishing Temperature on Mechanical Properties of a Nb-Microalloyed Steel Sheet

2010 ◽  
Vol 129-131 ◽  
pp. 1022-1028
Author(s):  
Daavood Mirahmadi Khaki ◽  
A. Akbarzadeh ◽  
Amir Abedi
Keyword(s):  
Mechanical Properties ◽  
Microalloyed Steel ◽  
Total Elongation ◽  
Controlled Rolling ◽  
Recrystallization Temperature ◽  
Effective Parameters ◽  
Steel Sheets ◽  
Intercritical Range ◽  
Nb Microalloyed Steel ◽  
Hot Rolled

Thermo mechanical processing and controlled rolling of microalloyed steel sheets are affected by several factors. In this investigation, finishing temperature of rolling which is considered as the most effective parameters on the final mechanical properties of hot rolled products has been studied. For this purpose, three different finishing temperatures of 950, 900 and 850 °C below the non-recrystallization temperature and one temperature of 800 °C in the intercritical range were chosen. It is observed that decreasing the finishing temperature causes increase of strength and decrease of total elongation. This is accompanied by more grain refinement of microstructure and the morphology was changed from polygonal ferrite to acicular one. Findings of this research provide suitable connection among finishing temperature, microstructural features, and mechanical properties of hot rolled Nb-microalloyed steel sheets.

scholarly journals Study of the thermal treatment modes influence on the forming of microstructure and specified complex of mechanical properties of high-strength sheet product with guaranteed level of hardness (400–450 HB) of low-alloyed steel

2019 ◽  
Vol 75 (4) ◽  
pp. 480-487
Author(s):  
M. Yu. Matrosov ◽  
P. G. Martynov ◽  
A. V. Mitrofanov ◽  
K. Yu. Barabash ◽  
T. V. Goroshko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fine Structure ◽  
Thermal Treatment ◽  
Hot Rolling ◽  
High Strength ◽  
Controlled Rolling ◽  
Alloyed Steel ◽  
Accelerated Cooling ◽  
Cold Forming ◽  
Low Alloyed Steel

High-strength sheet product of low-alloyed steel, used at manufacturing of heavy-loaded structures, must have, apart from wear resistance, high toughness, good weldability, ability to hot and cold forming, machinability and low cost. Combination of these properties based on forming fine grain austenite structure before the martensitic transformation at definite its thermal treatment modes. Results of study of microstructure, fine structure and mechanical properties of high-strength boron-containing low-alloyed steel after different technological methods of the rolled product manufacturing presented: high-temperature hot rolling and twostages controlled rolling with accelerated cooling followed by thermal treatment – quenching with tempering. Variants of optimal modes of thermal treatment determined, providing combination of high level of impact toughness under negative temperatures, hardness and strength properties of sheet product. The two considered in the article technological variants, comprising treatment of low-alloyed steel with boron (hot rolling and two-stages controlled rolling with accelerated cooling) followed by thermal treatment results in forming fine structure of tempered martensite, which provides high mechanical properties, meeting the made requirements. Depending on the heating temperature before quenching in the range 770–950 °С, the morphology of the actual steel grain is changing from elongated to equiaxed, which is connected with the metal recrystallization process during heating after plastic deformation. The study results obtained allow to optimize the thermal treatment processes of sheet product of low-alloyed boron containing steel for particular conditions of application.

scholarly journals Influence of thermal cycle of welding on structure and mechanical properties of haz metal in high-strength steel produced by controlled rolling

2018 ◽  
Vol 2018 (10) ◽  
pp. 9-13 ◽  
Author(s):  
V.D. Poznyakov ◽  
◽  
A.V. Zavdoveev ◽  
S.L. Zhdanov ◽  
A.V. Maksimenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength Steel ◽  
Thermal Cycle ◽  
High Strength ◽  
Controlled Rolling
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