scholarly journals The Effect of Nickel Contents on the Microstructure Evolution and Toughness of 800 MPa Grade Low Carbon Bainite Deposited Metal

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 709
Author(s):  
Jingwu Liu ◽  
Jian Sun ◽  
Shitong Wei ◽  
Shanping Lu
Keyword(s):  
Microstructure Evolution ◽  
Gas Metal Arc Welding ◽  
Lath Martensite ◽  
Control Unit ◽  
Low Carbon ◽  
Ni Content ◽  
Metal Arc Welding ◽  
Deposited Metal ◽  
Lath Bainite ◽  
Low Carbon Bainite

In this work, three deposited metals with different nickel (Ni) contents were produced by active gas metal arc welding (GMAW) in order to explore the influence of Ni on the microstructure evolution and toughness of 800 MPa grade low carbon bainite deposited metal. The results showed that microstructure of the deposited metals mainly consisted of lath bainite, lath martensite, coalesced bainite (CB), and retained austenite (RA), and that the toughness was closely related to two factors: CB and RA. RA in deposited metal could improve the toughness, while the CB would deteriorate the toughness of deposited metal. As the Ni content increased, a large amount of CB was generated in the deposited metals. The RA content increased from 1.5% to 5.7% with the content of Ni increasing from 5.5% to 6.5%. However, the RA content did not increase when the Ni content increased from 6.5% to 7.5%. Additionally, the smallest control unit of toughness in 800 MPa grade low carbon bainite deposited metals is the Bain Packet (BP) from the perspective of crystallography characteristics. This work provided a reference for the chemical composition design of 800 MPa grade steel welding consumables and showed that the toughness of the deposited metal could be improved effectively by increasing the RA content while suppressing the formation of CB.

scholarly journals Morphological and Crystallographic Characteristics of α Structure in a Low-Carbon Iron–Nickel Alloy

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 468 ◽  
Author(s):  
Gaojun Mao ◽  
Cyril Cayron ◽  
Xiuli Mao ◽  
Rui Cao ◽  
Roland Logé ◽  
...  
Keyword(s):  
Lath Martensite ◽  
Granular Bainite ◽  
Body Centered Cubic ◽  
Low Carbon ◽  
Electron Backscattered Diffraction ◽  
Dislocation Densities ◽  
Lath Bainite ◽  
Crystallographic Characteristics ◽  
Iron Nickel ◽  
Relationship Of

The features of α (body-centered cubic) structures were investigated in a low-carbon multicomponent alloy from morphological and crystallographic perspectives. In addition to apparent features of granular bainite and lamellar martensite, a morphological similarity can be found between lath martensite and lath bainite. Therefore, it is of interest to explore possible discrepancies between lath martensite and lath bainite from a crystallographic perspective. These microstructures were obtained by various cooling rates (i.e., water quenching, 5 °C/s, and 0.05 °C/s) and then were characterized by a combination of scanning electron microscopy and electron backscattered diffraction techniques. It is shown that: (1) Lath martensite (LM) formed in the samples that were water-quenched, and a mixture of LM and lath bainite (LB) and granular bainite (GB) formed in the samples cooled at rates of 5 °C/s and 0.05 °C/s, respectively; (2) A Kurdjumov-Sachs relationship was mostly found in as-quenched martensite, while a Greninger-Troiano relationship represented the orientation relationship of LB and GB; (3) As the cooling rate decreased, the dislocation densities in corresponding microstructures were reduced, while the tendency of variant grouping was enhanced.

scholarly journals Analysis of the Wall Geometry with Different Strategies for High Deposition Wire Arc Additive Manufacturing of Mild Steel

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 892 ◽  
Author(s):  
Eider Aldalur ◽  
Fernando Veiga ◽  
Alfredo Suárez ◽  
Jon Bilbao ◽  
Aitzol Lamikiz
Keyword(s):  
Additive Manufacturing ◽  
Gas Metal Arc Welding ◽  
Low Carbon Steel ◽  
Utilization Rate ◽  
High Deposition Rate ◽  
Low Carbon ◽  
Metal Arc Welding ◽  
Geometric Precision ◽  
Directed Energy ◽  
Wire Arc Additive Manufacturing

Additive manufacturing has gained relevance in recent decades as an alternative to the manufacture of metal parts. Among the additive technologies, those that are classified as Directed Energy Deposition (DED) are characterized by their high deposition rate, noticeably, Wire Arc Additive Manufacturing (WAAM). However, having the inability to produce parts with acceptable final surface quality and high geometric precision is to be considered an important disadvantage in this process. In this paper, different torch trajectory strategies (oscillatory motion and overlap) in the fabrication of low carbon steel walls will be compared using Gas Metal Arc Welding (GMAW)-based WAAM technology. The comparison is done with a study of the mechanical and microstructural characteristics of the produced walls and finally, addressing the productivity obtained utilizing each strategy. The oscillation strategy shows better results, regarding the utilization rate of deposited material and the flatness of the upper surface, this being advantageous for subsequent machining steps.

Effect of Welding Method on Weld Defects of ADB610 Steel

2010 ◽  
Vol 97-101 ◽  
pp. 818-821
Author(s):  
Tian Hui Zhang ◽  
Wen Min Liu ◽  
Ren Ping Xu ◽  
Bin Xu
Keyword(s):  
Arc Welding ◽  
Qualitative Difference ◽  
Rank Test ◽  
Low Carbon ◽  
Shielded Metal Arc Welding ◽  
Weld Defects ◽  
Metal Arc Welding ◽  
Low Carbon Bainite ◽  
The One ◽  
Average Size

Statistical analysis was carried on weld defects of low carbon bainite ADB610 steel using shielded metal arc welding (SMAW) and mixed active-gas arc welding (MAG). By Pareto diagram analysis, although the ratio of porosity air hole using SMAW is slightly higher than the one using MAG, there is no qualitative difference in ADB610 steel weld defect types between two welding methods. And the crack occurs seldom, which indicates ADB610 steel has lower crack-sensitivity using SMAW and MAG. By histogram analysis and rank test, it can be concluded that there is distinctive difference in defect size between SMAW and MAG, and the average size using SMAW is bigger than the one using MAG. So if possible, MAG is recommended for low carbon bainite ADB610 steel.

Effect of Shielding Gas Mixture on Gas Metal Arc Welding (GMAW) of Low Carbon Steel (LR Grade A)

2016 ◽  
Vol 705 ◽  
pp. 250-254 ◽  
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
M. Wirawan Pu ◽  
Fandi Alfarizi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Steel ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Shielding Gas ◽  
Weld Metals ◽  
Metal Arc Welding

The aimed of this research is to determine the feasibility and effect of the mixture of the shielding gas in the physical and mechanical properties. Low carbon steel LR grade A in a thickness 12 mm were joined in butt joint types using GMAW (Gas Metal Arc Welding) with groove’s gap 5 mm and groove angle’s 400 with variation of shielding gas composition. The composition of shielding gas that used were 100% Ar, 100 % CO2 and 50% Ar + 50 % CO2. The measured of mechanical properties with regard to strength, hardness and toughness using, tensile test, bending test, Vickers hardness Test, and Charpy impact test respectively. The physical properties examined with optical microscope. Results show that tensile strength of welding metals are higher than raw materials. Welds metal with mixing Ar + CO shielding gas has the highest tensile strength. Hardness of weld metals with the shielding gas 100% Ar, 100 % CO2 and 50% Ar + 50 % CO2 are 244.9; 209.4; and 209.4 VHN respectively. The temperature of Charpy test was varied to find the transition temperature of the materials. The temperature that used were –60°C, -40°C, -20°C, 0°C, 20°C , and room temperature. Weld metals with various shielding gas have similar trends of toughness flux that was corellated with the microstructure of weld .

Microstructure evolution simulation in hot rolled DP600 steel during gas metal arc welding

2013 ◽  
Vol 68 ◽  
pp. 107-116 ◽  
Author(s):  
A. Ramazani ◽  
Y. Li ◽  
K. Mukherjee ◽  
U. Prahl ◽  
W. Bleck ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Evolution Simulation ◽  
Metal Arc Welding ◽  
Hot Rolled

Microstructure Evolution during Warm Deformation of Low Carbon Steel with Dispersed Cementite

2007 ◽  
Vol 558-559 ◽  
pp. 505-510 ◽  
Author(s):  
J. Gallego ◽  
Alberto Moreira Jorge ◽  
O. Balancin
Keyword(s):  
Microstructure Evolution ◽  
Large Strain ◽  
Cell Structure ◽  
Lath Martensite ◽  
Low Carbon Steel ◽  
Testing Temperature ◽  
Equivalent Strain ◽  
Low Carbon ◽  
Ultrafine Grained ◽  
Ebsd Technique

The microstructure evolution and mechanical behavior during large strain of a 0.16%CMn steel has been investigated by warm torsion tests. These experiments were carried out at 685 °C at equivalent strain rate of 0.1 s-1. The initial microstructure composed of a martensite matrix with uniformly dispersed fine cementite particles was attained by quenching and tempering. The microstructure evolution during tempering and straining was performed through interrupted tests. As the material was reheated to testing temperature, well-defined cell structure was created and subgrains within lath martensite were observed by TEM; strong recovery took place, decreasing the dislocation density. After 1 hour at the test temperature and without straining, EBSD technique showed the formation of new grains. The flow stress curves measured had a peculiar shape: rapid work hardening to a hump, followed by an extensive flow-softening region. 65% of the boundaries observed in the sample strained to ε = 1.0 were high angle grain boundaries. After straining to ε = 5.0, average ferrite grain size close to 1.5 1m was found, suggesting that dynamic recrystallization took place. Also, two sets of cementite particles were observed: large particles aligned with straining direction and smaller particles more uniformly dispersed. The fragmentation or grain subdivision that occurred during reheating and tempering time was essential for the formation of ultrafine grained microstructure.

Experimental Study on Tensile Strength of Butt Joints for Mild Steel with Thickness 6mm Using Gas Metal Arc Welding (GMAW)

2017 ◽  
Vol 740 ◽  
pp. 155-160 ◽  
Author(s):  
Z.A. Zakaria ◽  
K.N.M. Hasan ◽  
M.F.A. Razak ◽  
Amirrudin Yaacob ◽  
A.R. Othman
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Heat Affected Zone ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Welding Current ◽  
Welding Parameter ◽  
Welding Parameters ◽  
Low Carbon ◽  
Metal Arc Welding

In this study, the effects of various welding parameters on welding strength in low carbon steel JIS G 3101 SS400, welded by gas metal arc welding were investigated. Welding current, arc voltage and travel speed are the variable parameters were studied in this study. The ultimate tensile strength, hardness and heat affected zone were measured for each specimen after the welding operations, and the effects of these parameters on strength were examined. Then, the relationship between welding parameter and ultimate tensile strength, hardness and heat affected zone were determined. Based on the finding, the best parameter is formulated and used to calculate the heat input.

Weldability of a Low Carbon High Strength Ti-Containing Bainitic Steel Produced by CSP

2010 ◽  
Vol 652 ◽  
pp. 275-278
Author(s):  
Ran Wei ◽  
Lin Cheng ◽  
Kai Ming Wu
Keyword(s):  
Heat Affected Zone ◽  
Acicular Ferrite ◽  
Gas Metal Arc Welding ◽  
Bainitic Ferrite ◽  
High Strength ◽  
Bainitic Steel ◽  
Low Carbon ◽  
Fine Grained ◽  
Metal Arc Welding ◽  
Strip Production

The weldability of a 700 MPa grade low carbon Ti-containing microalloyed bainitic steel produced by compact strip production (CSP) has been investigated by gas metal arc welding. Microstructural features of the welded joint of the investigated steel have been investigated utilizing optical and scanning electron microscopy (SEM). The microstructures in the heat affected zone (HAZ) consist of a predominantly bainitic ferrite and a proportion of acicular ferrite which formed on Ti-oxide and/or nitride particles. The acicular ferrite formed earlier effectively partitions prior austenite grains into smaller separate regions. The bainite transformed at lower temperatures is thus restricted in the smaller regions so that fine-grained mixed microstructures are obtained. The superior toughness of the weld joint of the investigated steel is attributed to the prior formation of acicular ferrite in the heat-affected zone.

Sign in / Sign up

Export Citation Format

Share Document