Development of High-Strength Steel Plates for Low-Temperature Use

1988 ◽  
Vol 110 (3) ◽  
pp. 171-176
Author(s):  
Y. Nakano ◽  
Y. Saito ◽  
K. Amano ◽  
M. Koda ◽  
Y. Sannomiya ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Yield Strength ◽  
Structural Steel ◽  
Welded Joints ◽  
High Strength Steel ◽  
Control Process ◽  
Charpy Impact ◽  
High Strength ◽  
Steel Plates

This paper describes the metallurgical approaches for producing 415MPa and 460MPa yield strength offshore structural steel plates and the mechanical properties of the steel plates and their welded joints. A thermo-mechanical control process (TMCP) was adopted to manufacture YP415MPa and YP460MPa steel plates with weldability comparable to conventional YP355MPa steel plates. The Charpy impact and CTOD tests of the steel plates and their welded joints proved to be very good.

Microstructure and Mechanical Properties of Ultra-High Strength Steel Plates with High Deformability

2010 ◽  
Vol 638-642 ◽  
pp. 3266-3271 ◽  
Author(s):  
Byoung Chul Hwang ◽  
Chang Gil Lee ◽  
Sung Hak Lee
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
High Strength Steel ◽  
Uniform Elongation ◽  
High Strength ◽  
Steel Plates ◽  
Ultra High Strength Steel ◽  
Temperature Transformation ◽  
High Deformability ◽  
Soft Ferrite

High deformability has been considered as a critical factor of ultra-high strength steel plates subjected to compressive, tensile, and bending deformation induced by large ground movements. In this paper, various dual phase microstructures consisting of soft ferrite and strong low-temperature transformation phases without deformation in the (austenite + ferrite) two-phase temperature region after controlled rolling were introduced and then the mechanical properties were discussed with emphasis on deformability such as yield ratio and uniform elongation. Ultra-high strength steel plates fabricated by a modified thermo-mechanical control process showed lower yield ratio of under 0.75 and higher uniform elongation of 5% as a minimum, as compared to commercial API X100 and X120 grade pipeline steels, without much sacrifice of Charpy impact properties because of an appropriate formation of soft ferrite and strong low-temperature transformation phases.

Influence of low-temperature tempering on structure and properties of welded joints of high-strength steel 30Kh2N2MF

2020 ◽  
Vol 2020 (6) ◽  
pp. 20-26
Author(s):  
O.A. Gaivoronskyi ◽  
◽  
V.D. Poznyakov ◽  
O.M. Berdnikova ◽  
T.O. Alekseenko ◽  
...  
Keyword(s):  
Low Temperature ◽  
Welded Joints ◽  
High Strength Steel ◽  
High Strength ◽  
Structure And Properties

Study on the Cooling Process of Low Yield Ratio 590-780MPa Grade Steel Plates for High-Rise Buildings

2011 ◽  
Vol 194-196 ◽  
pp. 292-295 ◽  
Author(s):  
Jian Kang ◽  
Zhao Dong Wang ◽  
Guo Dong Wang
Keyword(s):  
Mechanical Properties ◽  
Structural Steel ◽  
High Strength ◽  
Ferrite Matrix ◽  
Yield Ratio ◽  
Steel Plates ◽  
Air Cooling ◽  
Soft Phase ◽  
Cooling Temperature ◽  
Ultra Fast Cooling

To develop 590/780MPa grade low yield ratio structural steel, the effects of ultra fast cooling (UFC) new process on microstructure and mechanical properties were investigated. The results showed that the low yield ratio and high strength can be obtained by proper phase compositions including relative soft phase and hard phase. For the process of UFC + air cooling, when UFC final cooling temperature was 521°C, 22.5% M-A second hard phases were distributed on bainite ferrite matrix in steel No.A2. The mechanical properties can meet requirement of 590MPa grade low yield ratio structural steel. For the process of air cooling + UFC, when UFC initial cooling temperature was 781°C, the multiphase composed of 28.3% ferrite and other bainite / martensite lath structure can ensure the high strength and low yield ratio of steel No.B1. And performance indexes can meet the requirement of 780MPa grade low yield ratio structural steel.

scholarly journals Effect of Heat Treatment on Mechanical Properties and Microstructure Morphology of Low-Alloy High-Strength Steel

2016 ◽  
Vol 61 (2) ◽  
pp. 475-480
Author(s):  
K. Bolanowski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
High Strength Steel ◽  
High Strength ◽  
Strengthening Phase ◽  
Average Grain Size

Abstract The paper analyzes the influence of different heat treatment processes on the mechanical properties of low-alloy high-strength steel denoted by Polish Standard (PN) as 10MnVNb6. One of the findings is that, after aging, the mechanical properties of rolled steel are high: the yield strength may reach > 600 MPa, and the ultimate tensile strength is > 700 MPa. These properties are largely dependent on the grain size and dispersion of the strengthening phase in the ferrite matrix. Aging applied after hot rolling contributes to a considerable rise in the yield strength and ultimate tensile strength. The process of normalization causes a decrease in the average grain size and coalescence (reduction of dispersion) of the strengthening phase. When 10MnVNb6 steel was aged after normalization, there was not a complete recovery in its strength properties.

Microstructure and Mechanical Properties of Extra High Strength Heavy Steel Plate for Bridge Application

2014 ◽  
Vol 783-786 ◽  
pp. 859-866 ◽  
Author(s):  
Dong Sheng Liu ◽  
Chong Xiang Yue ◽  
Huan De Chen ◽  
Bing Gui Cheng
Keyword(s):  
Mechanical Properties ◽  
Arc Welding ◽  
Steel Plate ◽  
Control Process ◽  
High Strength ◽  
Submerged Arc Welding ◽  
Steel Plates ◽  
Weathering Steel ◽  
Weld Joints ◽  
Submerged Arc

Key parameters for thermomechanical control process (TMCP) and integrated welding operations have been determined to industrialize extra high strength micro-alloyed low carbon SiMnCrMoNiCu steel plates for bridge applications. Confocal Scanning Microscope was used to make In-situ observation on austenite grain growth during reheating. A Gleeble 3800 thermomechanical simulator was employed to investigate transformation behavior of the TMCP conditioned austenite. Integrated industrial rolling trial was conducted to correlate the laboratory observations and commercial production of the plates. Microstructure factors affecting the toughness of the steel were analyzed. Submerged-Arc Welding (SMAW) trails were conducted and the structures and mechanical properties of the weld joints characterized. The representative plate with thickness of 60 mm consisted of acicular ferrite (AF) + refined polygonal ferrite (PF) + granular bainite (GB) across the entire thickness section exhibit yield strength (YS) greater than 560 MPa in transverse direction and excellent Charpy V Notch (CVN) impact toughness greater than 100 J at-40 °C in the parent metal and the weld joints. These provide useful integrated database for producing advanced high strength steel plates via TMCP. Keywords: Thermo-Mechanical Control Process;Weathering Steel Plate for Bridge; Submerged-Arc Welding without Preheating

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