scholarly journals Microstructure and Strengthening Mechanisms in an HSLA Steel Subjected to Tempforming

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 48
Author(s):  
Anastasiia Dolzhenko ◽  
Alexander Pydrin ◽  
Sergey Gaidar ◽  
Rustam Kaibyshev ◽  
Andrey Belyakov
Keyword(s):  
Grain Size ◽  
Hsla Steel ◽  
High Strength ◽  
Carbide Precipitation ◽  
Strengthening Mechanisms ◽  
Plate Rolling ◽  
Ultrafine Grained ◽  
Quenched Steel ◽  
Low Alloyed Steel ◽  
Lamellar Type

An effect of tempforming on the microstructure, the carbide precipitation, and the strengthening mechanisms of high-strength low-alloyed steel has been analyzed. The quenched steel was subjected to 1 h tempering at a temperature of 873 K, 923 K, or 973 K followed by plate rolling at the same temperature. Tempforming resulted in the formation of an ultrafine grained lamellar-type microstructure with finely dispersed carbides of (Nb,V)C, Fe3C and Cr23C6. A decrease in tempforming temperature resulted in a reduction of the transverse grain size from 950 nm to 350 nm. Correspondingly, the size of Fe3C/Cr23C6 particles decreased from 90 nm to 40 nm while the size of (Nb,V)C particles decreased from 17 nm to 4 nm. Refining the tempformed microstructure with a decrease in thetempforming temperature provided an increase in the yield strength from 690 MPa to 1230 MPa.

scholarly journals Overview of HSS Steel Grades Development and Study of Reheating Condition Effects on Austenite Grain Size Changes

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1988
Author(s):  
Tibor Kvackaj ◽  
Jana Bidulská ◽  
Róbert Bidulský
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
High Strength Steel ◽  
Single Phase ◽  
Hsla Steel ◽  
High Strength ◽  
Strength Properties ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Steel Grades

This review paper concerns the development of the chemical compositions and controlled processes of rolling and cooling steels to increase their mechanical properties and reduce weight and production costs. The paper analyzes the basic differences among high-strength steel (HSS), advanced high-strength steel (AHSS) and ultra-high-strength steel (UHSS) depending on differences in their final microstructural components, chemical composition, alloying elements and strengthening contributions to determine strength and mechanical properties. HSS is characterized by a final single-phase structure with reduced perlite content, while AHSS has a final structure of two-phase to multiphase. UHSS is characterized by a single-phase or multiphase structure. The yield strength of the steels have the following value intervals: HSS, 180–550 MPa; AHSS, 260–900 MPa; UHSS, 600–960 MPa. In addition to strength properties, the ductility of these steel grades is also an important parameter. AHSS steel has the best ductility, followed by HSS and UHSS. Within the HSS steel group, high-strength low-alloy (HSLA) steel represents a special subgroup characterized by the use of microalloying elements for special strength and plastic properties. An important parameter determining the strength properties of these steels is the grain-size diameter of the final structure, which depends on the processing conditions of the previous austenitic structure. The influence of reheating temperatures (TReh) and the holding time at the reheating temperature (tReh) of C–Mn–Nb–V HSLA steel was investigated in detail. Mathematical equations describing changes in the diameter of austenite grain size (dγ), depending on reheating temperature and holding time, were derived by the authors. The coordinates of the point where normal grain growth turned abnormal was determined. These coordinates for testing steel are the reheating conditions TReh = 1060 °C, tReh = 1800 s at the diameter of austenite grain size dγ = 100 μm.

Multiple strengthening mechanisms in high strength ultrafine-grained Al–Mg alloys

2020 ◽  
Vol 771 ◽  
pp. 138613 ◽  
Author(s):  
Hao Wang ◽  
Hongwei Geng ◽  
Dengshan Zhou ◽  
Kodai Niitsu ◽  
Ondrej Muránsky ◽  
...  
Keyword(s):  
High Strength ◽  
Mg Alloys ◽  
Strengthening Mechanisms ◽  
Ultrafine Grained ◽  
Al Mg Alloys

High strength and ductile ultrafine-grained Cu–Ag alloy through bimodal grain size, dislocation density and solute distribution

2013 ◽  
Vol 61 (1) ◽  
pp. 228-238 ◽  
Author(s):  
K. Sitarama Raju ◽  
V. Subramanya Sarma ◽  
A. Kauffmann ◽  
Z. Hegedűs ◽  
J. Gubicza ◽  
...  
Keyword(s):  
Grain Size ◽  
Dislocation Density ◽  
High Strength ◽  
Solute Distribution ◽  
Ultrafine Grained ◽  
Bimodal Grain Size

scholarly journals Analysis of Influence of the Welding Procedure on Impact Toughness of Welded Joints of the High-Strength Low-Alloyed Steels

2020 ◽  
Vol 10 (7) ◽  
pp. 2205 ◽  
Author(s):  
Andreja Ilić ◽  
Ivan Miletić ◽  
Ružica R. Nikolić ◽  
Vesna Marjanović ◽  
Robert Ulewicz ◽  
...  
Keyword(s):  
Impact Toughness ◽  
Welded Joints ◽  
Hsla Steel ◽  
High Strength ◽  
Inert Gas ◽  
Welding Technology ◽  
First Case ◽  
Low Alloyed Steel ◽  
Welding Procedure ◽  
The Impact

This paper presents results of comparison of two welding procedures’ influence on selected properties of the welded joints of high-strength low-alloyed steel (HSLA), specifically the impact toughness and the hardness distribution in the specific zones of “single V” butt multiple-pass welded joints. Based on results obtained from experiments, the two applied welding technologies were evaluated. They differ by the welding grove geometry and by the applied root pass welding procedure. Both procedures use MAG (Metal Active Gas) welding for execution of the filling and covering passes, while the root passes are executed by the MMA (Manual Metal Arc) procedure in the first case and by the MIG (Metal Inert Gas) procedure in the second. Experimentally obtained values of the fracture energy of the welded samples for both procedures were smaller than the values for the parent metal, which confirms the fact that welding causes degradation of the mechanical properties of HSLA steel; thus, any welding technology parameters must be so selected to mitigate this deficiency.

Influence of Grain Size on Corrosion Resistance of a HSLA Steel

2012 ◽  
Vol 557-559 ◽  
pp. 143-146 ◽  
Author(s):  
Yan Tang Chen ◽  
Kai Guang Zhang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Mechanical Performance ◽  
Hsla Steel ◽  
High Strength ◽  
Corrosion Resistant ◽  
Hsla Steels ◽  
Mechanical Properties And Corrosion ◽  
Mn Steel

The mechanical performance, workability, weldability and corrosion resistance of structural high strength low alloy (HSLA) steels used in offshore engineering have been generally required. The effect of grain size on the corrosion resistant performance of a C-Mn structural steel has been investigated with stress on hunting a appropriate grain size to balance mechanical properties and corrosion resistant performance. The results showed that the C-Mn steel with grain size in 10～25μm scope provided expected mechanical properties and corrosion resistance.

Grain Refinement in Steels through Thermomechanical Processing

2005 ◽  
Vol 500-501 ◽  
pp. 39-48 ◽  
Author(s):  
Peter D. Hodgson ◽  
Hossein Beladi ◽  
Matthew R. Barnett
Keyword(s):  
Grain Size ◽  
Thermomechanical Processing ◽  
High Strength ◽  
Structural Steels ◽  
Dynamic Strain ◽  
Second Phase ◽  
Ultrafine Grained ◽  
Uniform Dispersion ◽  
Key Issues ◽  
Typical Range

The development of ultrafine grained microstructures in steels has received considerable attention in recent times. In many cases the aim is to produce high strength structural steels with minimal alloying. It is well established that for an equiaxed ferrite with a uniform dispersion of second phase, both the strength and toughness will be markedly improved if the grain size can be reduced to 1-2 µm, from the typical range of 5-10 µm. Means of achieving this through dynamic strain induced transformation are examined here, following a brief overview of some of the key issues encountered when attempting to refine the austenite in existing mill configurations. A number of deformation microstructure maps are developed to aid the discussion.

scholarly journals Механические свойства ультрамелкозернистого алюминия в области температур 4.2-300 K

2020 ◽  
Vol 62 (6) ◽  
pp. 930
Author(s):  
Т.С. Орлова ◽  
В.В. Шпейзман ◽  
А.М. Мавлютов ◽  
Т.А. Латынина ◽  
А.И. Аверкин ◽  
...  
Keyword(s):  
Grain Size ◽  
Yield Strength ◽  
Low Temperatures ◽  
High Pressure Torsion ◽  
High Strength ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Microstructure Parameters ◽  
Strength And Plasticity ◽  
High Level

Abstract The tensile curves of ultrafine-grained (UFG) aluminum structured by high pressure torsion (HPT) technique have been obtained at 4.2 and 77 K for the first time as well as the temperature dependence of its yield strength in the range 4.2–300 K. The analysis of the results in correlation with microstructure parameters and comparison with the results of such studies for UFG aluminum structured by equal-channel angular pressing (ECAP) technique has been performed. It has been shown that the HPT-processed aluminum has a significantly higher yield strength at low temperatures than the ECAP-processed aluminum. Combination of high strength and plasticity (440 MPa and 55%, respectively) was obtained at 4.2 K, which makes this material attractive for practical use at low temperatures. The analysis of the obtained results indicates that, at room and low (77 K) temperatures, the plasticity of the UFG aluminum with a grain size less than 1 μm largely depends on the nature of the grain size distribution, as well as on the type and state of the grain boundaries (equilibrium or nonequilibrium), which opens up prospects for controlling the value of plasticity by creating a given microstructural design while maintaining a high level of strength of ultrafine-grained materials.

Ultrafine Grained Low Carbon Steels Processed by Severe Plastic Deformation

2008 ◽  
Vol 584-586 ◽  
pp. 623-630 ◽  
Author(s):  
Sergey V. Dobatkin ◽  
P.D. Odessky ◽  
Svetlana V. Shagalina
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
High Strength ◽  
Carbon Steels ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Low Carbon Steels ◽  
Ultrafine Grained

The structure, mechanical and functional properties of ultrafine-grained low-carbon steels have been studied after severe plastic deformation (SPD) by high pressure torsion (HPT) and equalchannel angular pressing (ECAP). It is revealed that HPT of low carbon steels at a temperature below 0.3 Tm leads to the formation of nanocrystalline structure with a grain size of <100 nm or a mixture of oriented substructure and nanograins. ECAP under similar conditions leads to the formation of submicrocrystalline structure with a grain size of 200-300 nm. The initial martensitic state compared with the initial ferritic-pearlitic state of the low-carbon steels results in formation of finer structure after SPD and less intense grain growth upon heating, i.e., results in a higher thermal stability. Low-carbon low-alloy steels after ECAP are characterized by high strength (UTS > 1000 MPa) and plasticity (EL = 10-15%). The high-strength state after ECAP is retained upon tensile test testing up to a temperature of 500°C. The submicrocrystalline low-carbon steels after ECAP processing and subsequent heating is characterized by an increased impact toughness at test temperatures down to -40°C.

Effect of the Strain Rate on Mechanical Properties and Microstructure of High Strength Low Alloy Steel HC340LA

2012 ◽  
Vol 217-219 ◽  
pp. 467-470
Author(s):  
Xiao Hang Liu ◽  
Wen Jing Yuan ◽  
Hao Bin Tian ◽  
Fa Xi Diao
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Strain Rate ◽  
Alloy Steel ◽  
High Speed ◽  
Hsla Steel ◽  
High Strength ◽  
Static Tension ◽  
Low Alloy Steel

The mechanical properties and microstructure of the high strength low alloy HC340LA were obtained with different strain rate. The research shows that the better plasticity, higher tensile strength and yield ratio can be found in high speed tensile state than in quasi-static tension. The plasticity and tensile strength decrease with the increasing of the strain rate during the high speed tension. With the increasing of the strain rate, the grain size of the ferrite decreases and its distribution is uneven, and the grain boundaries increases. The HSLA steel HC340LA submit to obvious Ductile Frecture mechanism. The size of the dimples is more uniform, bigger and deeper with the strain rate 50 s-1 than with the strain rate 200 s-1. Therefore, the higher strain rate with over strain rate 50 s-1 has less Superscript textcontribution to the improvement of plasticity of the HSLA steel HC340LA.

scholarly journals Exploring the Strain Hardening Mechanisms of Ultrafine Grained Nickel Processed by Spark Plasma Sintering

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 65
Author(s):  
Lucía García de la Cruz ◽  
Mayerling Martinez Celis ◽  
Clément Keller ◽  
Eric Hug
Keyword(s):  
Grain Size ◽  
Strain Hardening ◽  
Spark Plasma Sintering ◽  
High Strength ◽  
Electron Backscattered Diffraction ◽  
Plasma Sintering ◽  
Ultrafine Grained ◽  
Spark Plasma ◽  
Deformed State ◽  
Hardening Mechanisms

Ultrafine grained (UFG) materials in the bigger grain size range (0.5–1) µm display a good combination of strength and ductility, unlike smaller size UFG and nanostructured metals, which usually exhibit high strength but low ductility. Such difference can be attributed to a change in plasticity mechanisms that modifies their strain hardening capability. The purpose of this work is to investigate the work hardening mechanisms of UFG nickel considering samples with grain sizes ranging from 0.82 to 25 µm. Specimens processed combining ball milling and spark plasma sintering were subjected to monotonous tensile testing up to fracture. Then, microstructural observations of the deformed state of the samples were carried out by electron backscattered diffraction and transmission electron microscopy. A lower strain hardening capability is observed with decreasing grain size. Samples in the submicrometric range display the three characteristic stages of strain hardening with a short second stage and the third stage beginning soon after yielding. Microstructural observations display a low fraction of low angle grain boundaries and dislocation density for the sample with d = 0.82 µm, suggesting changes in plasticity mechanisms early in the UFG range.

Sign in / Sign up

Export Citation Format

Share Document