Effects of Rolling Process on Microstructure and Yield Ratio in a High Strength Building Steel Plate

2013 ◽  
Vol 631-632 ◽  
pp. 637-642
Author(s):  
Tao Xiong ◽  
Hong Wei Yu ◽  
Shi Sen Wang ◽  
Han Xiong Dong ◽  
De Fa Li
Keyword(s):  
Tensile Strength ◽  
Steel Plate ◽  
Interlamellar Spacing ◽  
High Strength ◽  
Rolling Process ◽  
Area Ratio ◽  
Yield Ratio ◽  
Steel Plates ◽  
Refined Grains ◽  
Iron And Steel

The microstructures have been investigated in steel plates with different rolling processes to find the reasons of yield ratio overseted standard in few high strength building steel plates produced in Echeng Iron and Steel Corporation. The effects of rolling path, rolling path depress ratio on microstructure and properties. Some reasons of yield ratio overseted standard have been analyzed. The results show that decreasing rolling paths and increasing depress ratio refined grains but unchanged area ratio and interlamellar spacing of pearlite. Yield strength excessively increased but tensile strength unchanged increased yield ratio. So, excellent properties can be obtained by applying the optimization process.

Phase Transformation Rule, Microstructure and Properties of JG590 High Strength Steel

2007 ◽  
Vol 561-565 ◽  
pp. 29-32
Author(s):  
Yong Feng ◽  
Wei Hua Sun
Keyword(s):  
Tensile Strength ◽  
Phase Transformation ◽  
Yield Strength ◽  
Cooling Rate ◽  
High Strength Steel ◽  
High Strength ◽  
Steel Plates ◽  
Transformation Rule ◽  
Cooling Rates ◽  
Iron And Steel

The phase transformation rule, microstructures and properties of JG590 high strength steel produced in Jinan Iron and Steel Co. ltd. have been investigated in this paper. When the chemical composition of steel are given, the cooling rates after finished rolling affect on the properties of steel greatly. The yield strength and tensile strength increasing, the elongation and reduction of area decreasing as increasing of cooling rates after rolling. The main cause is due to appearance and increasing of Bainite and Martensite other than Ferrite and Pearlite in room temperature. The finished rolling temperature have distinct effects upon the mechanical properties of steel plates. Finished rolling at different temperature with the 0.5°C/s cooling rate, the tensile strength vary in 599-698MPa, the yield strength changed from 412 MPa to 536MPa. The elongation is between 30.4-40.5%. But when finished rolling at different temperature with the 2.0°C/s cooling rate, the tensile strength vary in 747-784MPa, the yield strength changed from 441 MPa to 601MPa. The strength index can both meet the requirements of employ. But the elongation is only 18.7-24.5%. This is related with production of lots of Bainite microstructure more than 2°C/s cooling rate. In the procedure of manufacture of JG590 high steel, the quickly cooling rate should be avoided to keep suitable microstructure and good elongation and toughness.

scholarly journals Steel Plate Cold-Rolled Section Steel Embedded High-Strength Concrete Low-Rise Shear Wall Seismic Performance

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Min Gan ◽  
Yu Yu ◽  
Liren Li ◽  
Xisheng Lu
Keyword(s):  
Bearing Capacity ◽  
Failure Mode ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
Steel Plate ◽  
Shear Walls ◽  
High Strength ◽  
Shear Wall ◽  
Steel Plates ◽  
Strength Concrete

Four test pieces with different steel plate center-to-center distances and reinforcement ratios are subjected to low-cycle repeat quasistatic loading to optimize properties as failure mode, hysteretic curve, skeleton curve, energy dissipation parameters, strength parameters, and seismic performance of high-strength concrete low-rise shear walls. The embedded steel plates are shown to effectively restrict wall crack propagation, enhance the overall steel ratio, and improve the failure mode of the wall while reducing the degree of brittle failure. Under the same conditions, increasing the spacing between the steel plates in the steel plate concrete shear wall can effectively preserve the horizontal bearing capacity of the shear wall under an ultimate load. The embedded steel plates perform better than concealed bracing in delaying stiffness degeneration in the low-rise shear walls, thus safeguarding their long-term bearing capacity. The results presented here may provide a workable basis for shear wall design optimization.

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.

Development of Reduced Rolling Process for Steel Plate

2012 ◽  
Vol 706-709 ◽  
pp. 2101-2106
Author(s):  
Xiu Hua Gao ◽  
Hui Fang Lan ◽  
Lin Xiu Du ◽  
Chun Lin Qiu
Keyword(s):  
Low Cost ◽  
New Technology ◽  
Rolling Process ◽  
Steel Plates ◽  
High Rate ◽  
Iron And Steel Industry ◽  
Iron And Steel ◽  
Heavy Plate ◽  
New Type ◽  
Microstructure And Mechanical Property

The low cost Q460 and Q550 steel plates were produced in the 4200mm wide and heavy plate mill using Normal Hot Rolling and High Rate Cooling (NHR+HRC) process. The effect of both rolling processes on microstructure and mechanical property was studied. The results indicate that new type process can realize the good match between microstructure and mechanical properties. Meanwhile the new technology can short rolling time, reduce alloying addition, and improve the output of mill, it is also promote iron and steel industry developing continuously.

Study on Precipitation Behavior of High Strength Steel Plate Strengthened Complexly by Titanium and Molybdenum

2011 ◽  
Vol 217-218 ◽  
pp. 812-818
Author(s):  
Hong Bin Wang ◽  
Sheng Li Li ◽  
Li Li ◽  
Peng Cheng Ma
Keyword(s):  
Electron Microscope ◽  
Steel Plate ◽  
High Strength ◽  
Optical Microscope ◽  
Steel Plates ◽  
Transmission Electron ◽  
Cold Rolled ◽  
Hot Rolled ◽  
Hot Rolled Steel ◽  
Energy Disperse Spectroscopy

The precipitation behaviors of hot rolling and cold rolled annealing steel plates strengthened complexly by titanium and molybdenum were studied in the paper. The microstructures and precipitate phases were analyzed using optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) with energy disperse spectroscopy (EDS). The results showed that the coarsening square TiN phase and the fine roundness (Ti,Mo)C phase were precipitated mostly in the hot rolled steel plate. As the finishing temperature decreased and coiling holding time increased, the quantity of fine precipitates increased. And also the fine round precipitates increased, dispersion expanded and shape of the phase being uniformed as the annealing temperature increased. Therefore, the strengthen effects can be improved effectively by a reasonable control toward titanium and molybdenum precipitation behaviors.

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

Development of 550 MPa Yield Strength Steel Plate for Offshore Structures

2004 ◽  
Author(s):  
Takahiro Kamo ◽  
Takeshi Urabe ◽  
Kazushi Ohnishi ◽  
Hirofumi Nakamura ◽  
Shuji Okaguchi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Yield Strength ◽  
Base Metal ◽  
Steel Plate ◽  
High Strength ◽  
Offshore Structures ◽  
Steel Plates ◽  
Offshore Structure ◽  
Copper Precipitation ◽  
High Toughness

Offshore structure steel with high strength of YS550MPa has been investigated. As for offshore structure steel, high toughness in welded joints is required in addition to that in base metal. TMCP type steel of up to YS420MPa grade is used widely, and up to YS500MPa grade is reported in some papers. However, steel of higher strength grade with good toughness and weldability will be beneficial to structures in strict conditions. To reach the YS550MPa requirement, hardening effect by Cu precipitation was utilized. Steel plates were designed with micro-alloyed low C-Mn-Cu-Ni-Cr-Mo system. The combination of the copper precipitation and TMCP technology can increase strength without deteriorating toughness and weldability. Heat treatment for Cu precipitation was carried out to optimize the balance of strength and toughness of the base metal. The developed steel also shows good HAZ CTOD toughness up to 76.2mm thickness in several welding conditions including after PWHT. The newly developed steel has the possibility to increase the flexibility to design large-sized structures.

Research on Hot Stamping Technology of High Strength Medium and Heavy Steel Plate

2020 ◽  
Vol 837 ◽  
pp. 81-86 ◽  
Author(s):  
Ning Ma ◽  
Yu Jie Ma ◽  
Ye Xuan Wang ◽  
Jian Yi Ji ◽  
Yi Chun Ji ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Temperature Difference ◽  
Production Efficiency ◽  
Steel Plate ◽  
Cooling System ◽  
Hot Stamping ◽  
High Strength ◽  
Steel Plates ◽  
Large Temperature ◽  
Forming Process

An innovative study on the high strength of U shaped steel plate was carried out. Through the two different cooling systems of hot stamping die obtained the two U shaped steel plates, founding that the cooling rate of U shaped steel plate obtained by bath water cooling system in the die was significantly higher than the steel plate obtained by cooling pipe in the die system, and had a smaller temperature difference, Which is a good solution to the problem the cooling rate of blank decreases with the thickness of blank increasing and the blank had a large temperature difference for badly uniform temperature quenching. This system is also greatly shorten the quenching time and improve the production efficiency in hot forming process.

scholarly journals Sliding Mode Control with Sliding Perturbation Observer-Based Strategy for Reducing Scratch Formation in Hot Rolling Process

2021 ◽  
Vol 11 (12) ◽  
pp. 5526
Author(s):  
Hyun-Hee Kim ◽  
Sung-Jin Kim ◽  
Sung-Min Yoon ◽  
Yong-Joon Choi ◽  
Min-Cheol Lee
Keyword(s):  
Hot Rolling ◽  
Steel Plate ◽  
Sliding Mode ◽  
Rolling Process ◽  
Steel Plates ◽  
Velocity Difference ◽  
Impact Forces ◽  
Hot Rolling Process ◽  
Finishing Mill ◽  
The Impact

In a hot rolling process, excessive friction between rollers and steel plates may lead to the formation of scratches on the steel plate. To reduce scratch formation in the finishing mill of the hot rolling process, two techniques are proposed in this work: flying touch and velocity synchronization. The proposed flying touch method can reduce the impact of the generated force when the upper roller collides with the steel plate. In addition, the proposed velocity synchronization method can decrease the frictional force resulting from the velocity difference between the rollers and steel plate. The effectiveness of the proposed methods was demonstrated through simulations and experiments using a 1/40 downscaled hot rolling simulator. The simulations and experimental results demonstrate that the proposed methods can reduce the magnitudes of friction and impact forces that lead to scratch formation on the steel plates in the hot rolling process.

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