scholarly journals Superior Mechanical Properties and Work-Hardening Ability of Ultrafine-Grained Quenched and Partitioned Steels Processed by a Novel Approach Involving Asymmetric Hot Rolling

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 872 ◽  
Author(s):  
Zhengyou Tang ◽  
Jianeng Huang ◽  
Xingchao Lu ◽  
Hua Ding ◽  
Dongmei Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hot Rolling ◽  
Work Hardening ◽  
Volume Fraction ◽  
Total Elongation ◽  
Low Alloy Steels ◽  
Direct Quenching ◽  
Novel Approach ◽  
Ultrafine Grained ◽  
Asymmetric Hot Rolling

An approach is proposed to enhance the mechanical properties and work-hardening (WH) ability of low-alloy steels. Using asymmetric hot rolling (AHR) and subsequent direct quenching (DQ) prior to the quenching and partitioning (Q&P) process, an ultrafine-grained Q&P steel with excellent combination of tensile strength of ~1000 MPa and total elongation of ~35% was obtained, which exhibited high WH exponent at higher strain induced by the higher volume fraction and higher stability of film-like retained austenite located between the martensite laths.

Effect of Ferrite Volume Fraction on Mechanical Properties of X80 Pipeline Steel

2014 ◽  
Vol 989-994 ◽  
pp. 212-215
Author(s):  
J. Liu ◽  
G. Zhu ◽  
W. Mao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Work Hardening ◽  
Single Phase ◽  
Volume Fraction ◽  
Pipeline Steel ◽  
X80 Pipeline Steel ◽  
Hardening Behavior ◽  
Two Phases ◽  
Better Than

The effect of volume fraction of ferrite on the mechanical properties including strength, plasticity and wok hardening was systematically investigated in X80 pipeline steel in order to improve the plasticity. The microstructures with different volume fraction of ferrite and bainite were obtained by heat-treatment processing and the mechanical properties were tested. The work hardening behavior was analyzed by C-J method. The results show that the small amount of ferrite could effectively improve the plasticity. The work hardening ability and the ratio of yield/tensile strength with two phases of ferrite/bainite would be obviously better than that with single phase of bainite. The improvement of plasticity could be attributed to the ferrite in which more plastic deformation was afforded.

Microstructural and Tribological Characterization of API X52 Dual-Phase Steel

2021 ◽  
Author(s):  
Gamri Hamza ◽  
Allaoui Omar ◽  
Zidelmel Sami
Keyword(s):  
Mechanical Properties ◽  
Dual Phase Steel ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Normal Load ◽  
Great Influence ◽  
Dual Phase ◽  
Martensite Volume Fraction ◽  
Direct Quenching ◽  
Disc Configuration

Abstract The effect of the morphology and the martensite volume fraction on the microhardness, the tensile, the friction and the wear behavior of API X52 dual phase (DP) steel has been investigated. Three different heat treatments were used to develop dual phase steel with different morphologies and with different amounts of martensite: Intermediate Quenching Treatment/Water (IQ); Step Quenching Treatment (SQ) and direct quenching (DQ). Tribological tests are conducted on DP steels using a ball-on-disc configuration under normal load of 5 N and at a sliding speed of 4 cm/s were used to study the friction and wear behavior of treated samples. Results show that the ferrite–martensite morphology has a great influence on the mechanical properties of dual phase steel. The steel subjected to (IQ) treatment attain superior mechanical properties compared to the SQ and the DQ treatments. On the other hand, it is also found that the friction coefficient and the wear rate (volume loss) decrease when the hardness and the martensite volume fraction increase. The steel with fine fibrous martensite provide good wear resistance.

Austenite Transformation Behavior and Mechanical Properties of Constructional V, Nb-Alloyed TRIP-Assisted Steel

2020 ◽  
Vol 864 ◽  
pp. 241-249
Author(s):  
Roman Kussa ◽  
Ihor Kushchenko ◽  
Volodymyr Andilakhai ◽  
Ivan Petryshynets ◽  
Vasily Efremenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Isothermal Holding ◽  
Total Elongation ◽  
Transformation Kinetics ◽  
Critical Temperatures ◽  
Austenite Transformation ◽  
Direct Quenching ◽  
Electron Scanning Microscopy ◽  
Multi Phase ◽  
Subcritical Temperature

The present article is aimed at studying the austenite transformation kinetics and tensile properties of constructional 0.2 wt%C-Si2Mn2CrMoVNb TRIP-assisted steel subjected to isothermal holding in the subcritical temperature range (350-650 °C with the step of 50 °C) after intercritical annealing at 770 °C. The study was fulfilled using optical microscopy (OLYMPUS GX-71), electron scanning microscopy (JEOL JSM-), dilatometric analysis, tensile testing, Vickers hardness measurements. The critical temperatures of the steel were found to be Ac1=750-760 °C and Ac3=930 °C. The results showed that austenite demonstrated increased stability to pearlite and bainite transformations with an incubation period of decades of seconds at any of the mentioned temperatures. The bainitizing treatment at 400 °C with holding of 300-600 s resulted in ferrite/bainite/retained austenite structure with precipitates of nanosized carbide (V,Nb)C providing an improved combination of mechanical properties as compared to direct quenching (YS=548-555 MPa, UTS=908-1000 MPa, total elongation=16-18 %, PSE index=14.6-18.0 GPa%, YS/UTS ratio=0.55-0.60). The contributions of different strengthening components were estimated in order to reveal the benefits of a multi-phase microstructure for constructional applications.

Effect of NbC volume fraction on mechanical properties of ultrafine grained Cu–NbC nanocomposites

2020 ◽  
Vol 790 ◽  
pp. 139674
Author(s):  
Chenguang Li ◽  
Wei Zeng ◽  
Dengshan Zhou ◽  
Jun Wang ◽  
Jiamiao Liang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Ultrafine Grained

scholarly journals Hot-Rolling and a Subsequent Direct-Quenching Process Enable Superior High-Cycle Fatigue Resistance in Ultra-High Strength Low Alloy Steels

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4651
Author(s):  
Min-Seok Baek ◽  
Young-Kyun Kim ◽  
Tae-Won Park ◽  
Jinhee Ham ◽  
Kee-Ahn Lee
Keyword(s):  
Fatigue Resistance ◽  
Hot Rolling ◽  
High Cycle Fatigue ◽  
Reduction Rate ◽  
High Strength ◽  
Low Alloy Steels ◽  
Cycle Fatigue ◽  
Near Surface ◽  
Direct Quenching ◽  
Quenching Process

The current study investigated the effect of hot rolling reduction rate of ultra-high strength low alloy steel manufactured via the direct quenching process on microstructure, tensile and high-cycle fatigue properties of the alloy. In order to control the reduction rate of ultra-high strength steels (UHSSs) differently, the steels were produced with two different thicknesses, 6 mm (46.2%—reduction rate, A) and 15 mm (11.5%—reduction rate, B). Then, the two alloys were directly quenched under the same conditions. Both the UHSSs showed martensite in the near surface region and auto-tempered martensite and bainite in the center region. Tensile results showed that alloy A with higher fraction of finer martensite had higher yield strength by about 180 MPa (1523 MPa) than alloy B. The alloy A was also found to possess a higher tensile strength (~2.1 GPa) than alloy B. In addition, alloy A had higher strength than B, and the elongation of A was about 4% higher than that of alloy B. High-cycle fatigue results showed that the fatigue limits of alloys A and B were 1125 MPa and 1025 MPa, respectively. This means that alloy A is excellent not only in strength but also high-cycle fatigue resistance. Based on the above results, the correlation between the microstructure and deformation behaviors were also discussed.

The Influence of Quenching Temperature on the Mechanical Properties of a Dual-Phase Steel with 0.094% C and 0.53% Mn

2015 ◽  
Vol 808 ◽  
pp. 28-33 ◽  
Author(s):  
Constantin Dulucheanu ◽  
Nicolai Bancescu ◽  
Traian Severin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Dual Phase Steel ◽  
Volume Fraction ◽  
Total Elongation ◽  
Metallographic Analysis ◽  
Dual Phase ◽  
Quenching Temperature ◽  
Offset Yield Strength ◽  
Martensite Structure

In this article, the authors have analysed the influence of quenching temperature (TQ) on the mechanical properties of a dual-phase steel with 0.094 % C and 0.53% Mn. In order to obtain a ferrite-martensite structure, specimens of this material have been the subjected to intercritical quenching that consisted of heating at 750, 770, 790, 810 and 830 °C, maintaining for 30 minutes and cooling in water. These specimens have then been subjected to metallographic analysis and tensile test in order to determine the volume fraction of martensite (VM) in the structure, ultimate tensile strength (Rm), the 0.2% offset yield strength (Rp0.2), the total elongation (A5) and the Rp0.2/Rm ratio.

Study on Microstructures and Mechanical Properties of Cold-Rolled C-Mn-Si-Al TRIP Steel

2010 ◽  
Vol 146-147 ◽  
pp. 678-681
Author(s):  
Zheng You Tang ◽  
Hua Ding
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Trip Steel ◽  
Retained Austenite ◽  
Volume Fraction ◽  
Total Elongation ◽  
Partial Substitution ◽  
Cold Rolled ◽  
Microstructures And Mechanical Properties

The effect of the partial substitution of Si by Al on the microstructures and the mechanical properties of cold rolled C-Mn-Si TRIP steel was investigated. The results show that the partial substitution of Si by Al could refine the microstructures, increase the volume fraction of ferrite and retained austenite. In addition, the excellent mechanical properties of the Al partial substituted TRIP steel could be obtained, the tensile strength, total elongation and strength-ductility of C-Mn-Si-Al TRIP steel are 739MPa, 38% and 28082MPa%, respectively.

Mechanical Properties of an Al-Mg-Sc Alloy Subjected to Intense Plastic Straining

2010 ◽  
Vol 638-642 ◽  
pp. 1952-1958 ◽  
Author(s):  
Rustam Kaibyshev ◽  
Elena Avtokratova ◽  
O.S. Sitdikov
Keyword(s):  
Mechanical Properties ◽  
Cold Rolling ◽  
Yield Stress ◽  
Room Temperature ◽  
Total Elongation ◽  
Warm Rolling ◽  
Ultimate Stress ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
High Reduction

Effect of intense plastic straining on rollability and service properties of an Al-6%Mg-0.3%Sc alloy was examined. Ultrafine-grained structure (UFG) was produced by equal-channel angular pressing (ECAP) to a strain of 8 at a temperature of 325oC. The formation of UFG structure resulted in increase in the yield stress from 223 MPa to 285 MPa and ultimate stress from 350 MPa to 389 MPa in comparison with initial hot extruded condition. Total elongation slightly decreased from 33% to 29%. After ECAP, the material was subjected to cold and isothermal warm rolling. The formation of UFG structure resulted in enhanced rollability of the present alloy at room temperature. Cold rolling with high reduction provides the development of heavily deformed microstructure with high dislocation density, while the isothermal warm rolling does not remarkably affect the microstructure produced by ECAP. The mechanical properties after ECAP and ECAP with subsequent isothermal rolling were roughly similar. In contrast, cold rolling to the same strain resulted in significant increase of yield stress (495 MPa) and ultimate stress (536 MPa). Total elongation attained was 13%.

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