scholarly journals The structure and properties of laser seam stepper system (LSS) welded the low alloy high strength steel DOCOL 1200M with martensitic structure

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Jacek Górka 1 ◽  
Andrzej Ozgowicz 2
Keyword(s):  
Welded Joints ◽  
Base Material ◽  
High Strength ◽  
Hardness Measurement ◽  
Welding Parameters ◽  
Martensitic Structure ◽  
Structure And Properties ◽  
Destructive Testing ◽  
Metallographic Examination ◽  
Actual Length

This paper will present the influence of joining process parameters on the structure and properties of overlapped welded joints of 1.8 mm DOCOL 1200M steel. The obtained welded joints were subjected to micro- and macroscopic metallographic examination and hardness measurement. The visual inspections and non-destructive testing made it possible to develop the field of welding parameters to allow obtaining full penetration joints (depending on requirements) or partial penetration joints. For present welding parameters, i.e. feed rate and weld length, which are constant, the actual length of weld is determined by welding frequency. In each case, the microscopic examinations revealed martensitic structure in the weld area, and with the increase in linear welding energy the size of martensite needles became larger, especially in relation to the base material. In HAZ, the martensitic structure is tempered. It has been shown that with appropriately selected parameters the Laser SEAM Stepper method is suitable for welding the DOCOL 1200M steel. With the increase in welding power, the penetration depth increases.

Influence of low-temperature tempering on structure and properties of welded joints of high-strength steel 30Kh2N2MF

2020 ◽  
Vol 2020 (6) ◽  
pp. 20-26
Author(s):  
O.A. Gaivoronskyi ◽  
◽  
V.D. Poznyakov ◽  
O.M. Berdnikova ◽  
T.O. Alekseenko ◽  
...  
Keyword(s):  
Low Temperature ◽  
Welded Joints ◽  
High Strength Steel ◽  
High Strength ◽  
Structure And Properties

scholarly journals Microstructure and Mechanical Properties of Modern 11%Cr Heat-Resistant Steel Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3430
Author(s):  
Grzegorz Golański ◽  
Jacek Słania ◽  
Marek Sroka ◽  
Paweł Wieczorek ◽  
Michał Urzynicok ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Martensitic Steel ◽  
Base Material ◽  
Hardness Measurement ◽  
Power Industry ◽  
Strength Properties ◽  
Typical Structure ◽  
Δ Ferrite ◽  
The Impact

In addition to good high-temperature creep resistance and adequate heat resistance, steels for the power industry must have, among other things, good weldability. Weldability of such steels is one of the criteria determining whether or not the material is suitable for applications in the power industry. Therefore, when materials such as martensitic steel Thor 115 (T115) are introduced into the modern power industry, the quality and properties of welded joints must be assessed. The paper presents the results of metallographic and mechanical investigations of T115 martensitic steel welded joints. The analysis was carried out on joints welded with two filler metals: WCrMo91 (No. 1) and EPRI P87 (No. 2). The scope of the investigations included: microstructural investigations carried out using optical, scanning and transmission electron microscopy and mechanical testing, i.e., Vickers microhardness and hardness measurement, static tensile test and impact test. The macro- and microstructural investigations revealed correct structure of the weld, without welding imperfections. The microstructural investigations of joint No. 1 revealed a typical structure of this type of joint, i.e., the martensitic structure with numerous precipitates, while in joint No. 2, the so-called Nernst’s layers and δ-ferrite patches were observed in the weld fusion zone as well as the heat affected zone (HAZ). The mechanical properties of the test joints met the requirements for the base material. A slight influence of the δ-ferrite patch on the strength properties of joint No. 2 was observed, and its negative effect on the impact energy of HAZ was visible.

Mechanical Behaviour of Welded Joints Achieved by Multi-Wire Submerged Arc Welding

2017 ◽  
Vol 1143 ◽  
pp. 52-57
Author(s):  
Elena Scutelnicu ◽  
Carmen Catalina Rusu ◽  
Bogdan Georgescu ◽  
Octavian Mircea ◽  
Melat Bormambet
Keyword(s):  
Mechanical Behaviour ◽  
Welded Joints ◽  
Arc Welding ◽  
Base Material ◽  
High Strength ◽  
Submerged Arc Welding ◽  
Steel Plates ◽  
Wire Saw ◽  
Api 5L X70 Steel ◽  
Submerged Arc

The paper addresses the development of advanced welding technologies with two and three solid wires for joining of HSLA API-5l X70 (High-strength low-alloy) steel plates with thickness of 19.1 mm. The experiments were performed using a multi-wire Submerged Arc Welding (SAW) system that was developed for welding of steels with solid, tubular and cold wires, in different combinations. The main goal of the research was to assess the mechanical performances of the welded joints achieved by multi-wire SAW technology and then to compare them with the single wire variant, as reference system. The welded samples were firstly subjected to NDT control by examinations with liquid penetrant, magnetic particle, ultrasonic and gamma radiation, with the aim of detecting the specimens with flaws and afterwards to reconsider and redesign the corresponding Welding Procedure Specifications (WPS). The defect-free welded samples were subjected to tensile, Charpy V-notch impact and bending testing in order to analyse and report the mechanical behaviour of API-5l X70 steel during multi-wire SAW process. The experimental results were processed and comparatively discussed. The challenge of the investigation was to find the appropriate welding technology which responds simultaneously to the criteria of quality and productivity. Further research on metallurgical behaviour of the base material will be developed, in order to conclude the complete image of the SAW process effects and to understand how the multi-wire technologies affect the mechanical and metallurgical characteristics of the API-5L X70 steel used in pipelines fabrication.

Improvement in Mechanical and Metallurgical Properties of Friction Stir Welded 6061-T6 Aluminum Alloys through Cryogenic Treatment

2019 ◽  
Vol 969 ◽  
pp. 490-495
Author(s):  
K. Tejonadha Babu ◽  
S. Muthukumaran ◽  
C.H. Bharat Kumar ◽  
C. Sathiya Narayanan
Keyword(s):  
Aluminum Alloys ◽  
Welded Joints ◽  
Cryogenic Treatment ◽  
Base Material ◽  
Cryogenic Cooling ◽  
Stir Zone ◽  
Welding Parameters ◽  
Cooling Rates ◽  
Friction Stir ◽  
Metallurgical Properties

An investigation has been made to improve the properties of the friction stir welded (FSW) 6061-T6 aluminum alloys. A cryogenic thermal treatment is developed for the joints during welding and its effects on mechanical and metallurgical properties, and precipitates are evaluated at various welding parameters. The friction stir welded joints with cryogenic treatment attained the better properties than the without cryogenic treatment. The improvement of properties was attributed to the refinement of grain size and to the introduction of a reduction in the softening region of the welded joints. Under cryogenic cooling rates, joints were experienced to the low temperature environments and faster cooling rates, which are contributed to enhance the hardness of the stir zone and heat affected zone regions and the formation of fine grain structure in the stir zone. The results indicated that the formation of finer grains of less than 5 µm in the stir zone, which is smaller than the joints of without cryogenic treatment. Subsequently, mechanical properties drastically improved and the joints achieved a maximum joint efficiency of 74% of the base material

scholarly journals JOINING THE COMBINATION OF AHSS STEEL AND HSLA STEEL BY RESISTANCE SPOT WELDING

2013 ◽  
Vol 7 (2) ◽  
pp. 75-78 ◽  
Author(s):  
Ľuboš Kaščák ◽  
Emil Spišák ◽  
Ivan Gajdoš
Keyword(s):  
Fuel Consumption ◽  
Welded Joints ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
High Strength ◽  
Quality Analysis ◽  
Vehicle Body ◽  
Welding Parameters ◽  
Resistance Spot ◽  
Ahss Steel

Abstract The paper deals with the optimization of parameters of resistance spot welding and quality analysis of welded joints made by combination of galvanized Advanced High Strength Steel and High Strength Low Alloy steel. It is an advanced material combination utilized in automotive industry to reduce weight of the vehicle body and consequently lowering the fuel consumption to achieve the lowest possible fuel consumption, high active and passive safety of passengers while decreasing the amount of emission. The quality of welded joints was evaluated by destructive tests and non-destructive tests. The shear tensile test according to STN 05 1122 standard was used. Some samples were prepared for metallographic analysis, where the influence of the welding parameters on the structure of welded joint and occurrence of pores in the weld metal caused by evaporation of zinc from the coating was observed.

The Low-Cycle Fatigue Strength of Laser-Welded Ultra-High-Strength Steel

2011 ◽  
Vol 473 ◽  
pp. 281-289 ◽  
Author(s):  
Markku Keskitalo ◽  
Kari Mäntyjärvi ◽  
Toni Kiuru
Keyword(s):  
Fatigue Strength ◽  
Energy Input ◽  
Weld Seam ◽  
Low Cycle Fatigue ◽  
High Surface ◽  
Base Material ◽  
High Strength ◽  
Welding Parameters ◽  
Light Weight ◽  
Design Strength

The UUltra -high -strength (UHS) steels are used in booms, transport vechicles and other light weight structures. It is well -known that it is possible to achieve a strong weld statically, as the base material, by using laser welding as a weld method [1]. The design strength of the light weight structure is often rather high. In the case of booms and transport vechilevehicles, there can be very high dynamic forces in the structure. Therefore it is necessary to study how much fatigue stress the weld seam can resist and at the same time find the optimal welding parameters. The 4 mm bainitic-martensitic UHS steel was welded with laser without filler material to lasercut seam edges by using different weld parameters. Argon gas was blown by pipe onr coaxial nozzle near the key hole and through a 60 mm gas nozzle after the keyhole. Also, the root side of the weld was shielded with argon. The welds were tested by using the bending fatigue test. The test stresses were 800 MPa and 700 MPa. The fatigue strength results showed that with the laser welded seams, the number of cycles wereas about three times lower than with the base material. The fatigue strength was slightly better in welds which were welded with lower energy input. In the case of the weld seam which was welded with lowest energy input by using 300 mm optics, there was some incomplete penetration due to tooexcessively high surface roughness ofat the weld seam edges.

Application of Multiple Methods of NDT for the Evaluation of Welded Joints in a Steel Bridge ASTM-A-588

2019 ◽  
Vol 287 ◽  
pp. 8-12
Author(s):  
Héctor C. Terán ◽  
Oscar Arteaga ◽  
F.S. Alcocer ◽  
Richard R. Navas ◽  
Stalin P. Mena ◽  
...  
Keyword(s):  
Welded Joints ◽  
Arc Welding ◽  
Base Material ◽  
Steel Bridge ◽  
Shielded Metal Arc Welding ◽  
Destructive Testing ◽  
Final State ◽  
Metal Arc Welding ◽  
Flux Cored Arc Welding ◽  
Non Destructive

This work is based on making a comparison of different inspection methods of non-destructive testing (NDT), to detect porosity, bite, undercut, splash, overlap, slag, concavity, lack of fusion and damage to base material, in welds of shielded metal arc welding (SMAW) and flux-cored arc welding (FCAW), made on a steel bridge ASTM-A-588. The main application of non-destructive tests is to evaluate the final state of a welded joint in critical points, in addition the fundamental objective is to ensure that the established acceptance and rejection criteria are met rigorously. For which non-destructive techniques are analyzed, such as the visual testing of welding on the beams of a bridge of length 35000 mm, subsequently, tests of inspection by liquid penetrant were used, based on the AWS D1.5 standard to confirm the failures in welded joints in ABA webs, an ultrasonic is also carried out using an SIUI CTS 602 equipment, finally to issue an acceptance and rejection criterion as determined by ASTM E165 and ASTM E2544-09.

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