Influence of laser welding heat input on HAZ cracking in newly developed Haynes 282 superalloy

2012 ◽  
Vol 28 (4) ◽  
pp. 431-436 ◽  
Author(s):  
L O Osoba ◽  
O A Ojo
Keyword(s):  
Laser Welding ◽  
Heat Input ◽  
Welding Heat Input ◽  
Haz Cracking

scholarly journals Effect of Heat Input on Porosity Defects in a Fiber Laser Welded Socket-Joint Made of Powder Metallurgy Molybdenum Alloy

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1433 ◽  
Author(s):  
Miao-Xia Xie ◽  
Yan-Xin Li ◽  
Xiang-Tao Shang ◽  
Xue-Wu Wang ◽  
Jun-Yu Pei
Keyword(s):  
Computed Tomography ◽  
Powder Metallurgy ◽  
Laser Welding ◽  
Fiber Laser ◽  
Heat Input ◽  
Dominant Role ◽  
Fusion Welding ◽  
Fiber Laser Welding ◽  
Welding Heat Input ◽  
Porosity Defects

Porosity defects are still a challenging issue in the fusion welding of molybdenum and its alloys due to the pre-existing interior defects associated with the powder metallurgy process. Fiber laser welding of end plug and cladding tube made of nanostructured high-strength molybdenum (NS-Mo) alloy was performed in this work with an emphasis on the role of welding heat input. The distribution and morphology of porosity defects in the welded joints were examined by computed tomography (CT) and scanning electron microscopy (SEM). Preliminary results showed that laser welding of NS-Mo under low heat input significantly reduced the porosity defects in the fusion zone. The results of computed tomography (CT) showed that when the welding heat input decreased from 3600 J/cm (i.e., 1200 W, 0.2 m/min) to 250 J/cm (i.e., 2500 W, 6 m/min), the porosity ratio of the NS-Mo joints declined from 10.7% to 2.1%. Notable porosity defects under high heat input were related to the instability of the keyhole, expansion and the merging of bubbles in the molten pool, among which the instability of the keyhole played the dominant role. The porous defects at low heat input were generated as bubbles released from the powder metallurgy base metal (BM) did not have enough time to overflow and escape.

scholarly journals A Study on Fusion Repair Process for a Precipitation Hardened IN738 Ni-Based Superalloy

1999 ◽  
Author(s):  
Dae-Young Kim ◽  
Jong-Hyun Hwang ◽  
Kwang-Soo Kim ◽  
Joong-Geun Youn
Keyword(s):  
Optimum Condition ◽  
Laser Welding ◽  
Laser Cladding ◽  
Heat Input ◽  
Arc Welding ◽  
Repair Process ◽  
Gas Tungsten Arc Welding ◽  
Repair Processes ◽  
Gas Tungsten Arc ◽  
Welding Heat Input

Several fusion repair processes such as laser cladding, laser welding and gas tungsten arc welding have been taken into consideration for repairing IN738 precipitation hardened Ni-based superalloy material. Effect of heat input on weld cracking susceptibility has been studied to obtain optimum condition for crack free welds. Variations in cracking susceptibility as a function of welding heat input is discussed with reference to metallurgical characteristics of the welds.

A Study on Fusion Repair Process for a Precipitation Hardened IN738 Ni-Based Superalloy

2000 ◽  
Vol 122 (3) ◽  
pp. 457-461 ◽  
Author(s):  
Dae-Young Kim ◽  
Jong-Hyun Hwang ◽  
Kwang-Soo Kim ◽  
Joong-Geun Youn
Keyword(s):  
Optimum Condition ◽  
Laser Welding ◽  
Laser Cladding ◽  
Heat Input ◽  
Arc Welding ◽  
Repair Process ◽  
Gas Tungsten Arc Welding ◽  
Repair Processes ◽  
Gas Tungsten Arc ◽  
Welding Heat Input

Several fusion repair processes such as laser cladding, laser welding and gas tungsten arc welding have been taken into consideration for repairing IN738 precipitation hardened Ni-based superalloy material. Effect of heat input on weld cracking susceptibility has been studied to obtain optimum condition for crack-free welds. Variations in cracking susceptibility as a function of welding heat input is discussed with reference to metallurgical characteristics of the welds. [S0742-4795(00)02003-2]

scholarly journals Effect of laser welding heat input on fatigue crack growth and CTOD fracture toughness of HSLA steel joints

2021 ◽  
Vol 11 ◽  
pp. 801-810
Author(s):  
Henrique Varella Ribeiro ◽  
Carlos Antonio Reis Pereira Baptista ◽  
Milton Sérgio Fernandes Lima ◽  
Marcelo Augusto Santos Torres ◽  
José Benedito Marcomini
Keyword(s):  
Fracture Toughness ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Laser Welding ◽  
Crack Growth ◽  
Heat Input ◽  
Hsla Steel ◽  
Welding Heat Input ◽  
Steel Joints

Effect of Laser Welding Heat Input on Microstructure and Properties of 26Cr-3.5Mo Ferritic Stainless Steel

2015 ◽  
Vol 42 (2) ◽  
pp. 0203005 ◽  
Author(s):  
刘腊腊 Liu Lala ◽  
胡绳荪 Hu Shengsun ◽  
申俊琦 Shen Junqi ◽  
马立 Ma Li ◽  
魏鑫 Wei Xin
Keyword(s):  
Stainless Steel ◽  
Laser Welding ◽  
Ferritic Stainless Steel ◽  
Heat Input ◽  
Microstructure And Properties ◽  
Welding Heat Input

scholarly journals Development of laser welding of high strength aluminium alloy 2024-T4 with controlled thermal cycle

2020 ◽  
Vol 326 ◽  
pp. 08005
Author(s):  
Mete Demirorer ◽  
Wojciech Suder ◽  
Supriyo Ganguly ◽  
Simon Hogg ◽  
Hassam Naeem
Keyword(s):  
Laser Beam ◽  
Laser Welding ◽  
Heat Input ◽  
Thermal Cycle ◽  
Laser Beam Welding ◽  
Base Material ◽  
High Strength ◽  
Cooling Rates ◽  
Aa 2024 ◽  
Welding Processes

An innovative process design, to avoid thermal degradation during autogenous fusion welding of high strength AA 2024-T4 alloy, based on laser beam welding, is being developed. A series of instrumented laser welds in 2 mm thick AA 2024-T4 alloys were made with different processing conditions resulting in different thermal profiles and cooling rates. The welds were examined under SEM, TEM and LOM, and subjected to micro-hardness examination. This allowed us to understand the influence of cooling rate, peak temperature, and thermal cycle on the growth of precipitates, and related degradation in the weld and heat affected area, evident as softening. Although laser beam welding allows significant reduction of heat input, and higher cooling rates, as compared to other high heat input welding processes, this was found insufficient to completely supress coarsening of precipitate in HAZ. To understand the required range of thermal cycles, additional dilatometry tests were carried out using the same base material to understand the time-temperature relationship of precipitate formation. The results were used to design a novel laser welding process with enhanced cooling, such as with copper backing bar and cryogenic cooling.

scholarly journals Microstructural Characteristics and Mechanical Properties of Friction Stir Spot Welded 2A12-T4 Aluminum Alloy

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Huijie Liu ◽  
Yunqiang Zhao ◽  
Xingye Su ◽  
Lilong Yu ◽  
Juncai Hou
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Fracture Mode ◽  
Heat Input ◽  
Tensile Shear ◽  
Microstructural Characteristics ◽  
Friction Stir ◽  
Welding Heat Input ◽  
Mixed Fracture ◽  
Spot Welded

2A12-T4 aluminum alloy was friction stir spot welded, and the microstructural characteristics and mechanical properties of the joints were investigated. A softened microstructural region existed in the joint, and it consisted of stir zone (SZ), thermal mechanically affected zone (TMAZ), and heat affected zone (HAZ). The minimum hardness was located in TMAZ, and the average hardness value in SZ can be improved by appropriately increasing welding heat input. The area of complete bonding region at the interface increased with increasing welding heat input because more interface metals were mixed. In a certain range of FSSW parameters, the tensile shear failure load of the joint increased with increasing rotation speed, but it decreased with increasing plunge rate or decreasing shoulder plunging depth. Two kinds of failure modes, that is, shear fracture mode and tensile-shear mixed fracture mode, can be observed in the tensile shear tests, and the joint that failed in the tensile-shear mixed fracture mode possessed a high carrying capability.

Determination of Heat Input in Tungsten Inert Gas and Laser Welding of Type Optim 960 QC Structural Steel Using Adams’ Equation for 2-D Heat Distribution

2017 ◽  
Vol 750 ◽  
pp. 45-52
Author(s):  
Sveto Cvetkovski
Keyword(s):  
Laser Welding ◽  
Heat Input ◽  
Arc Welding ◽  
Research Work ◽  
Laser Beam Welding ◽  
Peak Temperature ◽  
Efficiency Coefficient ◽  
Zone Recrystallization ◽  
Welding Processes

The heat input during conventional arc welding processes can be readily calculated knowing the power taken from the power source. The efficiency coefficient can be taken from the appropriate literature standards. Here, the intention of the performed research work was to develop a procedure for determination of heat input in arc and laser welding processes implementing Adams equation - modified Rykalin equation for two dimensional heat distributions (2-D). To realize this idea, it is necessary to determine two characteristic temperatures points in the HAZ with known peak temperature, and to determine distance between them. Implementing measured values for distance in Adams’ equation, heat input in arc welding can be directly determined in arc welded joints.In laser beam welding, the absorption of the beam in the metal is not known, so that the welding heat input cannot be calculated directly, and direct implementation of Adam’s equation is not possible i.e. absorption coefficient has to be determined first, and after that calculation of heat input is possible.The peak temperatures corresponding to specific microstructures can be obtained by performing welding simulation, by the Gleeble 1500 simulator in our case. As one of the peak temperatures, the melting temperature can be used corresponding to the fusion line, so that at least one characteristic peak temperature such as coarse grain zone, fine grin zone, intercritical zone, recrystallization, has to be determined by the simulation.Performed research showed that obtained values for heat input using Adam’s equation correspond pretty well with standard equation for heat input in arc welding.

Advances in joining technologies for the innovation of 21st century lightweight aluminium-CFRP hybrid structures

2022 ◽  
pp. 095440892110730
Author(s):  
Renangi Sandeep ◽  
Arivazhagan Natarajan
Keyword(s):  
Shear Strength ◽  
Laser Welding ◽  
Heat Input ◽  
Mechanical Performance ◽  
Current Knowledge ◽  
Ultrasonic Welding ◽  
Hybrid Structures ◽  
Joint Shear Strength ◽  
Hybrid Joints ◽  
Welding Processes

In the twenty-first century, the application of carbon fiber reinforced polymer (CFRP) materials in the vehicle industry are growing rapidly due to lightweight, high specific strength, and elasticity. In the automobile and aerospace industries, CFRP needs to be joined with metals to build complete structures. The demand for hybrid structures has prompted research into the combination of CFRP and metals in manufacturing. Aluminium and CFRP structures combine the mechanical properties of aluminium with the superior physical and chemical properties of CFRP. However, joining dissimilar materials is often challenging to achieve. Various joining technologies are developed to produce hybrid joints of CFRP, and aluminium alloys include conventional adhesives, mechanical and thermal joining technologies. In this review article, an extensive review was carried out on the thermal joining technologies include laser welding, friction-based welding technologies, ultrasonic welding, and induction welding processes. The article primarily focused on the current knowledge and process development of these technologies in fabricating dissimilar aluminium and CFRP structures. Besides, according to Industry 4.0 requirements, additive manufacturing-based techniques to fabricate hybrid structures are presented. Finally, this article also addressed the various improvements for the future development of these joining technologies. Ultrasonic welding yields the maximum shear strength among the various hybrid joining technologies due to lower heat input. On the other hand, laser welding produces higher heat input, which deteriorates the mechanical performance of the hybrid joints. Surface pretreatments on material surfaces prior to joining showed a significant effect on joint shear strength. Surface modification using anodizing is considered an optimal method to improve wettability, increasing mechanical interlocking phenomena.

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