Quantitative Untersuchung des Ausscheidungszustandes von mikrolegierten Stählen und sein Zusammenhangmitden mechanischen Eigenschaften / Quantitative Investigation ofthe Precipitation State of Microalloyed Steels, and its Connection with the Mechanical Properties

1989 ◽  
Vol 26 (1) ◽  
pp. 17-24
Author(s):  
H.-G. Hillenbrand ◽  
C. Prasser ◽  
P. Schwaab
Keyword(s):  
Mechanical Properties ◽  
Microalloyed Steels ◽  
Quantitative Investigation

Effect of the Time between Last Deformation Pass and Accelerated Cooling on the Mechanical Properties in Nb and Nb-Mo Microalloyed Steels

2016 ◽  
Vol 716 ◽  
pp. 281-290
Author(s):  
Gorka Larzabal ◽  
Nerea Isasti ◽  
J.M. Rodriguez-Ibabe ◽  
Isabel Gutiérrez ◽  
P. Uranga
Keyword(s):  
Mechanical Properties ◽  
Charpy Impact ◽  
Holding Time ◽  
Microalloyed Steels ◽  
Accelerated Cooling ◽  
Low Carbon ◽  
Compression Tests ◽  
Electron Backscattered Diffraction ◽  
Microstructural Refinement ◽  
Deformation Pass

The microstructural refinement induced when the holding time between last deformation pass and accelerated cooling is reduced, affects the mechanical properties in low carbon Nb and Nb-Mo microalloyed steels. Plane strain compression tests were performed and mechanical property samples machined in order to quantify this effect using tensile and Charpy impact tests. A complete microstructural characterization was carried out using electron backscattered diffraction (EBSD) measuring unit size distributions and homogeneity of complex microstructures. The synergetic combination of Nb and Mo elements modifies the final microstructures and, therefore, affects the contribution of different strengthening mechanisms, such as substructure, precipitation hardening and dislocation density. Even though strength is not clearly affected by the reduction of the holding time after the last deformation pass, Charpy properties are considerably improved in the case of the Nb steel. The presence of MA islands in the Nb-Mo steel limits the beneficial effect of the microstructural refinement and toughness remains unmodified.

Effect of Nb and V in the Development of Texture and Plastic Strain Ratio in Low Carbon Microalloyed Steels Produced by A.S.T. Technology

2005 ◽  
Vol 500-501 ◽  
pp. 279-286
Author(s):  
Carlo Mapelli ◽  
Roberto Venturini ◽  
Antonio Guindani
Keyword(s):  
Mechanical Properties ◽  
Strain Ratio ◽  
Tensile Tests ◽  
Microalloyed Steels ◽  
Low Carbon ◽  
Plastic Strain Ratio ◽  
Steel Technology ◽  
Back Scattering ◽  
Carbon Microalloyed ◽  
Hot Rolled

The effects of Nb and V on the anisotropy and textures featuring the hot rolled low carbon microalloyed steels produced by A.S.T. (Arvedi Steel Technology) have been studied as a function of the final coiling temperatute Tcoiling. Mechanical properties and r-values for twelve steels have been determined through tensile tests performed on three main different directions: 0°, 45°, 90° to the rolling one. The samples have been analysed by EBSD (Electron Back Scattering Diffraction) to identify the textures developed during the process. The relations among the chemical composition of the steels (i.e. C, N, Nb, V contents), the mechanical properties, the temperature during the coiling operations, the textures and the formability properties have been pointed out.

Influence of Composition and Processing Conditions on Mechanical Properties and Fish-Scale Resistance of Microalloyed Steels for Double-Face Vitreous Enamelling

2005 ◽  
Vol 500-501 ◽  
pp. 527-534
Author(s):  
Joachim Schöttler ◽  
V. Flaxa ◽  
Klaus Hulka
Keyword(s):  
Mechanical Properties ◽  
Microalloyed Steels ◽  
Fish Scale ◽  
Processing Conditions ◽  
Rolled Steel ◽  
Cold Rolled Steel ◽  
Steel Sheets ◽  
Scale Resistance ◽  
Cold Rolled ◽  
High Fish

Hot- and cold-rolled steel sheets are the most important substrate materials for enamelling applications. Currently, industry is actively seeking ways to widen the area of application of hotrolled steel sheets for double-face enamelling. Another important task is search for new steel compositions that might substitute for currently used open-coil annealed, cold-rolled steel sheet for direct white enamelling applications. The purpose of this research project was the investigation of influence of chemical composition and processing conditions of several microalloyed steels on mechanical properties and fish-scale resistance of hot and cold rolled sheets. The results show that a high fish-scale resistance of the hot-rolled steel is achieved by creating a high volume fraction of fine precipitates (nitrides, carbides, carbonitrides, sulphides, etc.). By partial replacement of titanium with other carbide and nitride forming elements, such as niobium and/or boron, the suitability of cold-rolled IF steels for white direct-on enamelling can be remarkably improved without open-coil annealing. However, the processing conditions have to be tuned to ensure high fish-scale resistance without impairing formability.

Refined and Uniform Microstructure with Superior Mechanical Properties in Medium Plate Microalloyed Steel with Reduction in Mn-Content during Ultrafast Cooling

2016 ◽  
Vol 879 ◽  
pp. 2066-2071 ◽  
Author(s):  
Zhao Dong Wang ◽  
Bin Wang ◽  
Yan Mei Li ◽  
Bing Xing Wang ◽  
Guo Dong Wang
Keyword(s):  
Mechanical Properties ◽  
Microalloyed Steel ◽  
Manganese Content ◽  
Plate Thickness ◽  
Ferrite Matrix ◽  
Microalloyed Steels ◽  
Accelerated Cooling ◽  
Low Alloy Steels ◽  
Uniform Microstructure ◽  
Ultrafast Cooling

We describe here the relationship between electron microscopy and mechanical property studies in industrially processed titanium bearing microalloyed steel plates that involved processing using the recently developed ultrafast cooling (UFC) approach. Given that the segregation of manganese is generally responsible for microstructural banding in low-alloy steels, which can deteriorate the tensile property in the direction of thickness, the manganese-content was reduced by ~0.6-0.8% with the objective to obtain uniform microstructure across the thickness of the steel plate. Besides, non-uniform distribution of accelerated cooling along the thickness direction also leads to inhomogeneous microstructure across the plate thickness. In order to obtain near-uniform microstructure and similar mechanical properties from the surface to the center of plate, fast and effective cooling process is necessary. In this regard, refined and uniform microstructure that was free of microstructural banding was obtained via UFC process across the plate thickness, with strict control and faster cooling rate on the run-out table. Furthermore, grain refinement and random precipitation in the ferrite matrix contributed ~100 MPa toward yield strength. The study underscores the potential of processing medium and heavy plates of titanium bearing microalloyed steels plates with uniform and refined microstructure across the thickness via thermo-mechanical controlled processing (TMCP) involving UFC.

Sign in / Sign up

Export Citation Format

Share Document