scholarly journals Effect of Aluminum on Microstructure and Mechanical Properties of Weld Metal of Q960 Steel

Crystals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Zongxuan Zou ◽  
Zhengjun Liu ◽  
Xingyu Ai ◽  
Dan Wu
Keyword(s):  
Tensile Strength ◽  
Weld Metal ◽  
Impact Energy ◽  
Hsla Steel ◽  
Low Carbon Steel ◽  
High Strength ◽  
Low Carbon ◽  
Cored Wire ◽  
Al Content ◽  
The Impact

High-strength low-alloy (HSLA) steel is used in important steel structural members because of its strength and plastic toughness. Q960 steel is HSLA steel obtained by adding an appropriate amount of alloy elements and quenching and tempering treatment on the basis of ordinary low-carbon steel. This kind of steel has strong hardenability due to the alloy elements added. Cold cracks, embrittlement and softening of the heat-affected zone easily occur after welding. In particular, the low-temperature impact toughness cannot meet the requirements and limits its use. In this paper, self-shielded welding is used to adjust the content of aluminum in flux-cored wire. The relationship between weld metal (WM) microstructure and strength and properties was studied by tensile test and impact test, and the influence mechanism of Al content on weld metal microstructure and properties was analyzed. The results show that when the content of Al is 0.21%, the impact energy at 0 °C~−60 °C is the best, the tensile strength can reach 1035 MPA and the number of pores is small. The size of inclusions in WM is mostly less than 1.0 μm Al2O3 spherical oxide. It can become the center of acicular ferrite (AF) and increase the nucleation probability. However, with the increase of Al content, large irregular AlN inclusions are produced, which reduces the tensile strength and impact energy of the welded joint.

The Effect of Boron on the Impact Energy of Low-Carbon Steel Weld Metal at Low Temperatures

2018 ◽  
Vol 7 (2) ◽  
pp. 143-152 ◽  
Author(s):  
Seyyed Reza Amirabadizade ◽  
Shamsodin Shafinia ◽  
Hamed Sabet ◽  
Shamsodin Mirdamadi ◽  
Hossein Ebrahimnezhad-Khaljiri
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Impact Energy ◽  
Low Temperatures ◽  
Low Carbon Steel ◽  
Steel Weld ◽  
Low Carbon ◽  
Steel Weld Metal ◽  
The Impact

scholarly journals Effect of Carbon Partitioning, Carbide Precipitation, and Grain Size on Brittle Fracture of Ultra-High-Strength, Low-Carbon Steel after Welding by a Quenching and Partitioning Process

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 747 ◽  
Author(s):  
Farnoosh Forouzan ◽  
M. Guitar ◽  
Esa Vuorinen ◽  
Frank Mücklich
Keyword(s):  
Grain Size ◽  
Carbon Steel ◽  
Weld Zone ◽  
Low Carbon Steel ◽  
High Strength ◽  
Precipitate Size ◽  
Low Carbon ◽  
Quenching And Partitioning ◽  
High Level ◽  
The Impact

To improve the weld zone properties of Advanced High Strength Steel (AHSS), quenching and partitioning (Q&P) has been used immediately after laser welding of a low-carbon steel. However, the mechanical properties can be affected for several reasons: (i) The carbon content and amount of retained austenite, bainite, and fresh martensite; (ii) Precipitate size and distribution; (iii) Grain size. In this work, carbon movements during the partitioning stage and prediction of Ti (C, N), and MoC precipitation at different partitioning temperatures have been simulated by using Thermocalc, Dictra, and TC-PRISMA. Verification and comparison of the experimental results were performed by optical microscopy, X-ray diffraction (XRD), Scanning Electron Microscop (SEM), and Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive Spectroscopy (EDS) and Electron Backscatter Scanning Diffraction (EBSD) analysis were used to investigate the effect of martensitic/bainitic packet size. Results show that the increase in the number density of small precipitates in the sample partitioned at 640 °C compensates for the increase in crystallographic packets size. The strength and ductility values are kept at a high level, but the impact toughness will decrease considerably.

Effect of Ti on the Microstructures and Toughness of TMCP-600 Steel Weld Metals

2013 ◽  
Vol 746 ◽  
pp. 462-466
Author(s):  
Jin Hyun Koh ◽  
Bok Su Jang
Keyword(s):  
Weld Metal ◽  
Impact Energy ◽  
Acicular Ferrite ◽  
Gas Metal Arc Welding ◽  
Control Process ◽  
High Strength ◽  
Weld Metal Microstructure ◽  
Metal Microstructure ◽  
The Impact ◽  
Ti Content

The Ti addition effect on the characteristics of weld metal, such as impact energy, microstructure and nonmetallic inclusions, was investigated to develop a suitable gas metal arc welding wire for the high strength of TMCP (Thermo Mechanical Control Process)-600 steel. The fraction of acicular ferrite which was known to be a favorable weld metal microstructure for toughness was increased with Ti content from 0.002% to 0.025%, The impact energy of weld metal was increased whereas the ductile to brittle transition temperature was decreased with increasing Ti content. The size of nonmetallic inclusion was decreased while the density of inclusions was decreased with increasing Ti content. It was found that Ti content on the weld metal toughness had a plus effect by increasing the fraction of acicular ferrite in the weld metal microstructure.

scholarly journals Effects of Austempering on the Microstructure, Corrosion and Mechanical Properties of AISI 1018 Steel

2021 ◽  
Author(s):  
Oluwole Daniel Adigun ◽  
Muyideen Adebayo Bodude ◽  
Aanuoluwapo Rebecca Adigun ◽  
Babatunde Abiodun Obadele ◽  
Abdullahi Olawale Adebayo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Room Temperature ◽  
Low Carbon Steel ◽  
Salt Bath ◽  
Isothermal Transformation ◽  
Low Carbon ◽  
Micro Hardness ◽  
Microstructural Investigation

Abstract In this study, the effects of austempering on the microstructure, mechanical properties (micro hardness, impact energy and tensile strength) and corrosion behaviours of AISI 1018 low carbon steel were evaluated. The steel specimens were subjected to heat treatment by austenitizing at 830°C, maintained in this condition for 90 min before rapid cooling in a NaNO3 salt bath sustained at 300°C for isothermal transformation for additional 50 min and finally allowed to air cool to room temperature. The as-received and the austempered samples were tested for corrosion in both 0.5M aqueous acidic (HCl) and 0. 5M alkaline (NaOH) media. Microstructural investigation using scanning electron microscope (SEM) reveals transformation from ferrite/pearlite phases to bainite over the austempering process. Interestingly, significant improvements of 15.7% to 95.7% in the various mechanical properties (micro hardness, impact energy and tensile strength) and corrosion resistance in both media were observed.

Developing High Strength-High Toughness Low Carbon Steel Using Combined V-Ti-Micro-Alloying and Different Thermo-Mechanical Treatments

2018 ◽  
Vol 786 ◽  
pp. 57-64 ◽  
Author(s):  
Ahmed Hamed ◽  
Mamdouh Eissa ◽  
Abdelhakim Kandil ◽  
Omnia Ali ◽  
Taha M. Mattar
Keyword(s):  
Tensile Strength ◽  
Carbon Steel ◽  
Impact Toughness ◽  
Low Carbon Steel ◽  
Chemical Compositions ◽  
Air Cooling ◽  
Low Carbon ◽  
Steel Alloys ◽  
Grain Sizes ◽  
The Impact

This work aims at designing and developing low carbon steel alloys to meet the high tensile strength, high ductility and high impact toughness properties. The effect of solid solution mechanism, precipitation hardening, as well as grain refinement were developed with different Manganese content (0.78-2.36wt%) combined with Vanadium(0.008-0.1wt%) and Titanium (0.002-0.072wt%) microalloying additions. The controlled thermo-mechanical treatments and chemical compositions play a big role in developing the microstructure and the corresponding mechanical properties. Therefore, the studied chemical compositions were treated thermo-mechanically by two different ways of changing start and finish forging temperatures with subsequent air cooling. The first way by start forging from 1050 to 830oC and the second from 950 to730oC. The second way of forging process developed finer grain sizes and higher ultimate tensile strengths for all the studied steel alloys. In spite of finer grain sizes, the impact toughness value was lower in the second regime due to detrimental influence of precipitation strengthening in the ferrite. A combination of 544 MPa yield strength, 615 MPa ultimate tensile strength, 20% elongation and 138 Joule impact toughness has been attained.

Effect of Different Annealing Process for Microstructure and Properties of 1200MPa HSLA Steel

2015 ◽  
Vol 713-715 ◽  
pp. 2653-2657
Author(s):  
Yu Pei ◽  
Zhe Gao ◽  
Yi Liu ◽  
Shi Qian Zhao ◽  
Chang Yu Xu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Hsla Steel ◽  
High Strength ◽  
Annealing Process ◽  
Air Cooling ◽  
Low Carbon ◽  
Slow Cooling ◽  
Microstructure And Properties

For C-Si-Mn low carbon HSLA(High Strength Low Alloyed) steel, the influence of microstructure and properties were researched on the different annealing processes. The result showed that the microstructure at room temperature of the steel were polygonal ferrite, island martensite and punctate bainite. With the increase of the annealing temperature, the content of martensite and bainiteincreased and the content of ferrite decreased. Accordingly, tensile strengthincreased from 1069MPa to 1498MPa, and the elongation decreased from 13.8% to 5.1%. With the increase of the overaging temperature, tensile strength decreased from 1315MPa to 1152MPa, and the elongationincreased from8.5% to9.8%. Finally, the optimum annealing process obtained that the annealing temperature was 820°C for 80s, slow cooling to 680°C, water quenching to room temperature, the overaging temperature was 280°C for 300s and air cooling to room temperature. The material obtained higher tensile strength and better elongation.

An Experimental Investigation of Relationship between surface Hardness and Strength of Locally produced TMT 500W bar in Bangladesh

2020 ◽  
Vol 11 (1) ◽  
pp. 113-122
Author(s):  
Sazzad Ahmad ◽  
Wahidur Rahman Sajal
Keyword(s):  
Tensile Strength ◽  
Testing Machine ◽  
Surface Hardness ◽  
Low Carbon Steel ◽  
High Strength ◽  
Local Market ◽  
Low Carbon ◽  
Core Hardness ◽  
Short Time ◽  
Deformed Bar

The high-strength mild steel bars (usually low carbon steel) are widely used for structural purposes throughout the world including Bangladesh. The strength of these deformed barsis measured through a sample decimation process via Universal Testing Machine (UTM), after which the broken pieces are discarded as scrap for recycling. Therefore, measuring the hardness of steel could be a good indication of strength and will involve less sample and short time for testing. The strength–hardness relationship for steel and cast iron is well defined. However, the TMT 500W deformed bar using in Bangladesh has different structural phenomena due to its unique fabrication technique. Therefore, it is necessary to understand how the strength varies with hardness for this grade of steel. The current research aims to explore the hardness–strength relationship for TMT (Thermomechanical Treatment) 500W bar as an alternate of the tensile test to minimize the wastage, cost and time of testing. Several TMT 500W bars were collected from the local market and measured the Rockwell Hardness B (HRB), strength and other relevant macroscopic/microscopic parameters. Finally, two empirical relationships of yield and tensile strength have been established using rim hardness, core hardness, and rim thickness data. The actual strength data shows a good agreement with present findings and the result variation is found less than 2% and 3% in the case of yield strength and tensile strength respectively. Journal of Engineering Science 11(1), 2020, 113-122

STRIMEK

Alloy Digest ◽  
1984 ◽  
Vol 33 (9) ◽  
Keyword(s):  
Hsla Steel ◽  
Low Carbon Steel ◽  
High Strength ◽  
Heat Treating ◽  
Bend Strength ◽  
Low Carbon ◽  
Strip Steel ◽  
Reinforced Plastic ◽  
Low Weight ◽  
Microalloying Elements

Abstract STRIMEK is a Super High-Strength Low-Alloy (HSLA) steel. It is a microalloyed high-strength steel. Its unique properties are obtained in a carefully moniored process where microalloying elements are added and a special type of heat teatment is carried out. Strimek is lighter than an equivalent component of the same strength in low-carbon steel, aluminum or fibreglass-reinforced plastic. It is available in three grades, all of which have the unique combination of high strength, good formability and good weldability. Strimek is recommended where high strength at low weight is needed. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and bend strength. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-401. Producer or source: Uddeholm Strip Steel AB.

Effect of Alloy Addition on Mechanical Properties and Decarburization Sensitivity of Spring Steel

2012 ◽  
Vol 476-478 ◽  
pp. 188-193
Author(s):  
Jun Tian ◽  
Shun Xue ◽  
Guo Guang Cheng ◽  
Kuo Chih Chou
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Energy ◽  
Induction Furnace ◽  
High Strength ◽  
Spring Steel ◽  
Vacuum Induction Furnace ◽  
High Toughness ◽  
Alloy Addition ◽  
The Impact

The mechanical properties and decarburization layer depths after heat treatment have been investigated for the experimental steels，which were melted by means of 10Kg vacuum induction furnace in the laboratory . It has been confirmed that additions of silicon and vanadium can improve strength of the steels and, the tensile strength of the steels increases with silicon content from 1.4% up to 2.0%. The reduction of carbon content and the addition of carbide forming elements decrease the decarburization sensitivity of the steels tested. The tensile strengths of the steels with carbon less than 0.5% are between 1016.88 to 1674.64 MPa, and the impact energy between 15.50 to 34.50 J, which are compared with the tensile strength of 1160.89MPa, the impact energy of 19.00 J for 55SiCrV. The steels with optimized compositions, which consists of 0.4~0.5% C, 1.6~2.0% Si, 0.8% Cr, 0.2% V, have a satisfactory property with high strength, high toughness and good anti-decarburization.

Trimming of Advanced High Strength Steels

2005 ◽  
Author(s):  
Sergey F. Golovashchenko ◽  
Andrey M. Ilinich
Keyword(s):  
Carbon Steel ◽  
Low Carbon Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
Advanced High Strength Steels ◽  
Stretch Flanging ◽  
Alternative Materials ◽  
The Impact ◽  
Current Standards

Modern product design and manufacturing often utilizes a wide variety of materials. Where once low carbon steel predominated, a variety of different materials such as aluminum alloys and advanced high-strength steels (AHSS) are now being utilized. Although such alternative materials may provide a variety of benefits in manufacturing and design, these same materials may present difficulties when subjected to manufacturing processes originally designed for low carbon steel. One such manufacturing area where difficulties may arise is in trimming operations. A defect that may arise directly in the trimming operation are burrs. Burrs decrease the quality and accuracy of stamped parts and cause splits in stretch flanging and hemming. Current standards limit the production of burrs through accurate alignment of the upper and lower edges of the trim knives. The clearance between the shearing edges should be less than 10% of the material thickness. For automotive exterior sheet, this requires a gap less than 0.06mm. Unfortunately, tolerances often exceed the capabilities of many trim dies resulting in the production of burrs. To satisfy the current standards of quality and to meet customer satisfaction, stamped parts frequently need an additional deburring operation, which is often accomplished as a metal-finish operation and conducted manually. The objective of the research described in this paper was to study the mechanisms of burr generation and the impact on AHSS formability in stretch flanging. Results on both the conventional trimming process and a recently developed robust trimming process, which has the potential to expand tolerances of trim die alignment, will be discussed.

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