scholarly journals Effect of Welding Thermal Cycles on Microstructure and Mechanical Properties of Simulated Heat Affected Zone for a Weldox 1300 Ultra-High Strength Alloy Steel

2016 ◽  
Vol 61 (1) ◽  
pp. 127-132 ◽  
Author(s):  
M. St. Węglowski ◽  
M. Zeman ◽  
A. Grocholewski
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Heat Affected Zone ◽  
High Strength Steel ◽  
High Strength ◽  
Parent Material ◽  
Cooling Time ◽  
Microstructure And Mechanical Properties ◽  
Ultra High Strength Steel ◽  
The Impact

In the present study, the investigation of weldability of ultra-high strength steel has been presented. The thermal simulated samples were used to investigate the effect of welding cooling time t8/5 on microstructure and mechanical properties of heat affected zone (HAZ) for a Weldox 1300 ultra-high strength steel. In the frame of these investigation the microstructure was studied by light and transmission electron microscopies. Mechanical properties of parent material were analysed by tensile, impact and hardness tests. In details the influence of cooling time in the range of 2,5 ÷ 300 sec. on hardness, impact toughness and microstructure of simulated HAZ was studied by using welding thermal simulation test. The microstructure of ultra-high strength steel is mainly composed of tempered martensite. The results show that the impact toughness and hardness decrease with increase of t8/5 under condition of a single thermal cycle in simulated HAZ. The increase of cooling time to 300 s causes that the microstructure consists of ferrite and bainite mixture. Lower hardness, for t8/5 ≥ 60 s indicated that low risk of cold cracking in HAZ for longer cooling time, exists.

Physical Simulation of Weldability of Weldox 1300 Steel

2013 ◽  
Vol 762 ◽  
pp. 551-555 ◽  
Author(s):  
Marek Stanislaw Węglowski ◽  
Marian Zeman ◽  
Miroslaw Lomozik
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Physical Simulation ◽  
High Strength ◽  
Parent Material ◽  
Cooling Time ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Transformation Diagrams ◽  
The Impact

In the present study, the investigation of weldability of new ultra-high strength - Weldox 1300 steel has been presented. The thermal simulated samples were used to investigate the effect of welding cooling time t8/5 on the microstructure and mechanical properties of the heat affected zone (HAZ). In the frame of these investigation the microstructure was studied by the light (LM) and transmission electron microscopies (TEM). It has been shown that the microstructure of the Weldox 1300 steel is composed of tempered martensite, and inside the laths the minor precipitations mainly V(CN) and molybdenum carbide Mo2C were observed. Mechanical properties of parent material were analysed by the tensile, impact and hardness tests. In details the influence of cooling time in the range of 2,5 - 300 s. on hardness, impact toughness and microstructure of simulated HAZ was studied by using welding thermal simulation test. The results show that the impact toughness and hardness decrease with the increase of t8/5 under the condition of a single thermal cycle in simulated HAZ. The continuous cooling transformation diagrams (CCT-W for welding conditions) of Weldox 1300 steel for welding purposes was also elaborated. The steel Weldox 1300 for cooling time in the range of 2,5 - 4 s showed martensite microstructure, for time from 4 s to 60 s mixture of martensite and bainite, and for longer cooling time mixture of ferrite, bainite and martensite. The results indicated that the weldability of Weldox 1300 steel is limited and to avoid the cold cracking the preheating procedure or medium net linear heat input should be used.

Study of processing, microstructure and mechanical properties of hot rolled ultra-high strength steel

2018 ◽  
Vol 46 (6) ◽  
pp. 535-541 ◽  
Author(s):  
Tihe Zhou ◽  
David Overby ◽  
Peter Badgley ◽  
Chris Martin-Root ◽  
Xiang Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Strength Steel ◽  
High Strength ◽  
Microstructure And Mechanical Properties ◽  
Ultra High Strength Steel ◽  
Hot Rolled

scholarly journals Impact Toughness of Gas Metal Arc Welded HY-80 Steel Plate at Sub-zero Temperatures

2019 ◽  
Vol 269 ◽  
pp. 06003
Author(s):  
Herry Oktadinata ◽  
Winarto Winarto
Keyword(s):  
Impact Toughness ◽  
Weld Joint ◽  
Heat Affected Zone ◽  
High Strength Steel ◽  
Steel Plate ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Coarse Grain ◽  
Fracture Appearance ◽  
The Impact

Various welding methods are widely applied in large fabrication of high strength steel. However, commonly the problem occurs where a coarse grain is formed near fusion zone causing reduce the impact toughness due to the weld joint become brittle. Ductility and toughness in a coarse grain heat affected zone (CGHAZ) is low due to the formation of coarsening grain size. The objective of this research is to investigate the microstructure evolution, impact toughness and fracture appearance at sub-zero temperatures of the high strength steel arc welded. The steel that used in this experiment is a HY-80 steel welded by gas metal arc welding (GMAW) with a mixture of argon and carbon dioxide (90%Ar and 10%CO2) and ER100S solid wire. Microstructure observation and Charpy V-notch (CVN) tests were performed on the weld joint which consist of base metal (BM), heat affected zone (HAZ), and weld metal (WM). The CVN tests on the HY-80 steel plate at various temperatures (20, -20, -60 and -80 °C) show impact toughness decrease when the test temperature decrease. The CVN tests on the HY-80 weld joint at a temperature of 80 °C show the lowest impact toughness was measured at WM (61 J) and followed fusion line-FL (101 J) with brittle fracture appearance.

Microstructure and Mechanical Properties of Low Alloy Ultra-High Strength Steel Microalloyed with Cerium

2021 ◽  
Vol 871 ◽  
pp. 53-58
Author(s):  
Yue Yue Jiang ◽  
Zhao Dong Wang ◽  
Xiang Tao Deng ◽  
R.D.K. Misra
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Rare Earth Element ◽  
Impact Energy ◽  
High Strength Steel ◽  
Earth Element ◽  
High Strength ◽  
Matrix Composition ◽  
Microstructure And Mechanical Properties ◽  
Ultra High Strength Steel

This study aims to investigate the influences of rare earth element cerium (Ce) on microstructure and mechanical properties of low alloy ultra-high strength steel. The strength, plasticity, and impact toughness of steels with 0.0367% Ce and without Ce were tested. The influence mechanism of Ce on the microstructure and mechanical properties were investigated by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and electron back scattered diffraction (EBSD). The results showed that the addition of Ce improved the comprehensive mechanical properties of low alloy ultra-high strength steel. In particular, the plasticity and toughness were improved obviously. The addition of Ce increased the elongation from 9.47% to 10.49%, and the low-temperature impact energy from 50J to 58J. The elongation and impact energy increased by 10.77% and 16%, respectively. And the yield strength of all samples remained above 1400 MPa. The rare earth element Ce did not change the matrix composition phase which were martensite. However, the addition of Ce increased the proportion of high-angle grain boundary from 33.2% to 40.2%. In addition, the Ce make the inclusions denatured and hence spherical inclusion with small size can be obtained. The EDS results showed that rare earth and harmful elements P and O formed inclusions, which as a purifier for the molten steel and hindered the formation of the large-size composite inclusions.

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