scholarly journals STRENGTH AND FRACTURE TOUGHNESS OF THE WELDED JOINTS MADE OF HIGH-STRENGTH FERRITIC STEEL

2013 ◽  
Vol 7 (4) ◽  
pp. 226-229 ◽  
Author(s):  
Ihor Dzioba ◽  
Tadeusz Pała ◽  
Ilkka Valkonen
Keyword(s):  
Fracture Toughness ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Ferritic Steel ◽  
Base Material ◽  
High Strength ◽  
Experimental Results ◽  
Strength Characteristics ◽  
Fusion Line ◽  
Weld Material

Abstract The paper presents experimental results of the characteristics of strength and fracture toughness of the material from the different zones of welded joints made of different participation of the linear welding energy. Strength characteristics and fracture toughness were determined in the weld material, in the area of fusion line, in the material of the heat affected zone and in the base material

scholarly journals TEMPERATURE DEPENDENCY OF FRACTURE TOUGHNESS OF HIGH-STRENGTH FERRITIC STEEL HARDOX-400

2013 ◽  
Vol 7 (4) ◽  
pp. 222-225 ◽  
Author(s):  
Ihor Dzioba ◽  
Robert Pała ◽  
Tadeusz Pała
Keyword(s):  
Fracture Toughness ◽  
Ferritic Steel ◽  
High Strength ◽  
Experimental Results ◽  
Strength Characteristics ◽  
Temperature Dependency ◽  
Temperature Changes ◽  
Temperature Range

Abstract The paper presents experimental results of the changes of strength and fracture toughness characteristics of high-strength ferritic steel Hardox-400 in the temperature range from -100 OC to +20 OC. It has been shown that the strength characteristics values increase linearly with lowering the temperature. Changes of fracture toughness characteristics from temperature are more complex and they are dependent on thickness of the tested specimens

scholarly journals Verification of Strength of the Welded Joints by using of the Aramis Video System

2017 ◽  
Vol 11 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Tadeusz Pała ◽  
Ihor Dzioba ◽  
Jarosław Gałkiewicz
Keyword(s):  
Fracture Toughness ◽  
Tensile Properties ◽  
Welded Joints ◽  
Base Material ◽  
High Strength ◽  
Tensile Tests ◽  
Strength Analysis ◽  
Heat Affect Zone ◽  
Video System ◽  
Weld Material

AbstractIn the paper are presented the results of strength analysis for the two types of the welded joints made according to conventional and laser technologies of high-strength steel S960QC. The hardness distributions, tensile properties and fracture toughness were determined for the weld material and heat affect zone material for both types of the welded joints. Tests results shown on advantage the laser welded joints in comparison to the convention ones. Tensile properties and fracture toughness in all areas of the laser joints have a higher level than in the conventional one. The heat affect zone of the conventional welded joints is a weakness area, where the tensile properties are lower in comparison to the base material. Verification of the tensile tests, which carried out by using the Aramis video system, confirmed this assumption. The highest level of strains was observed in HAZ material and the destruction process occurred also in HAZ of the conventional welded joint.

scholarly journals DIFFUSION OF HYDROGEN IN WELDED JOINTS OF STRUCTURAL STEELS

2017 ◽  
Vol 21 (6) ◽  
pp. 85-95 ◽  
Author(s):  
N. N. Sergeev ◽  
A. N. Sergeev ◽  
S. N. Kutepov ◽  
A. E. Gvozdev ◽  
E. V. Ageev
Keyword(s):  
Diffusion Coefficient ◽  
Weld Metal ◽  
Heat Affected Zone ◽  
Welded Joints ◽  
Chemical Potential ◽  
Weld Zone ◽  
Base Material ◽  
High Strength ◽  
Low Alloy Steels ◽  
Alloy Steels

High-strength low-alloy steels are widely used in the construction of welded metal structures. The main advantage of these steels is good combination of strength and toughness, and weldability. However, when welding high strength low alloy steels during cooling of the weld to a temperature below 150-100 °C there may be a risk of formation of bulk crystal structures defects in the weld zone - cold cracks. It was experimentally established that one of the factors contributing to the formation of cold cracks may be the occlusion of hydrogen in the atmosphere of arc plasma in the solidifying weld metal, from which diffusion hydrogen may diffuse to different areas of the weld after cooling. Hydrogen cracking typically has a tendency to slow down i.e. cracks can occur several days after the completion of welding process. As a rule, hydrogen induced cracking occurs either in the original steel in the heat-affected zone or in the weld metal, which is important, topical and long been researched by various scientific schools. Modern technologies of high strength low alloy steels processing have significantly improved the quality of the base material by reducing the amount of carbon and impurities, which has increased the stability of weld in the heat affected zone (HAZ) to hydrogen induced cold cracking. The paper presents modern approaches to the definition of diffusion coefficient of hydrogen in welded joints of high-strength low-alloy steels. Taking into account the temperature, the gradient of chemical potential and continuity conditions there has been considered the process of mass transfer of hydrogen under the influence of diffuse inhomogeneous mediums. It has been shown that the local effects of changing pressure and chemical potential are described using the equation of generalized potential of the diffusing substance. Our paper presents analytical expressions to determine the apparent diffusion coefficient of hydrogen in different local areas of a welded joint depending on temperature.

Determination of Strain and Stress Fields in Laser Welded Joints by Means of the Aramis Video System

2016 ◽  
Vol 250 ◽  
pp. 151-156
Author(s):  
Tadeusz Pala ◽  
Jarosław Galkiewicz ◽  
Ihor Dzioba
Keyword(s):  
Welded Joints ◽  
True Strain ◽  
Base Material ◽  
High Strength ◽  
Stress Fields ◽  
Heat Affect Zone ◽  
Video System ◽  
Weld Material ◽  
Strain Stress

In the paper are presented the tests carried out on the specimens made of boot laser welded joints of high strength ferritic steel S960QC. The tensile properties materials for materials the weld, heat affect zone and base of welded joints were determined. For verification of strength welded joints during tensile test and registration of the strain fields created during joint loading used the optical video system Aramis. On the basis of strains, and using the true strain-stress dependencies, the stresses in the weld material and in the base material at the area of the occurrence of strain localization were determined.

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.

scholarly journals A Study on Rotary Friction Welding of Titanium Alloy (Ti6Al4V)

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ho Thi My Nu ◽  
Truyen The Le ◽  
Luu Phuong Minh ◽  
Nguyen Huu Loc
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
Friction Welding ◽  
Base Material ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Experimental Results ◽  
Thermomechanical Model ◽  
Rotary Friction Welding

The selection of high-strength titanium alloys has an important role in increasing the performance of aerospace structures. Fabricated structures have a specific role in reducing the cost of these structures. However, conventional fusion welding of high-strength titanium alloys is generally conducive to poor mechanical properties. Friction welding is a potential method for intensifying the mechanical properties of suitable geometry components. In this paper, the rotary friction welding (RFW) method is used to study the feasibility of producing similar metal joints of high-strength titanium alloys. To predict the upset and temperature and identify the safe and suitable range of parameters, a thermomechanical model was developed. The upset predicted by the finite element simulations was compared with the upset obtained by the experimental results. The numerical results are consistent with the experimental results. Particularly, high upset rates due to generated power density and forging pressure overload that occurred during the welding process were investigated. The performances of the welded joints are evaluated by conducting microstructure studies and Vickers hardness at the joints. The titanium rotary friction welds achieve a higher tensile strength than the base material.

High Temperature, Low Cycle Fatigue Characterization of P91 Weld and Heat Affected Zone Material

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
T. P. Farragher ◽  
S. Scully ◽  
N. P. O'Dowd ◽  
C. J. Hyde ◽  
S. B. Leen
Keyword(s):  
High Temperature ◽  
Weld Metal ◽  
Heat Affected Zone ◽  
Low Cycle Fatigue ◽  
Base Material ◽  
Strain Response ◽  
Cycle Fatigue ◽  
Stress Strain ◽  
Weld Material ◽  
The Cross

The high temperature low cycle fatigue behavior of P91 weld metal (WM) and weld joints (cross-weld) is presented. Strain-controlled tests have been carried out at 400 °C and 500 °C. The cyclic behavior of the weld material (WM) and cross-weld (CW) specimens are compared with previously published base material (BM) tests. The weld material is shown to give a significantly harder and stiffer stress–strain response than both the base material and the cross-weld material. The cross-weld tests exhibited a cyclic stress–strain response, which was similar to that of the base material. All specimen types exhibited cyclic softening but the degree of softening exhibited by the cross-weld specimens was lower than that of the base material and all-weld tests. Finite element models of the base metal, weld metal and cross-weld test specimens are developed and employed for identification of the cyclic viscoplasticity material parameters. Heat affected zone (HAZ) cracking was observed for the cross-weld tests.

Structure Analyses of Experimental Welds Designed for Repair Welding of VVER 1000 Presssure Vessel

2015 ◽  
Vol 647 ◽  
pp. 131-140 ◽  
Author(s):  
Miroslava Matějová ◽  
Dagmar Jandová ◽  
Josef Kasl
Keyword(s):  
Heat Affected Zone ◽  
Microstructural Analysis ◽  
Base Material ◽  
Fusion Line ◽  
Structure Transformation ◽  
Repair Welding ◽  
Weld Joints ◽  
The Third ◽  
Energy Inputs ◽  
Welding Metal

Microstructural analysis and microhardness measurement of experimental repair weld joints were carried out in heat affected zone (HAZ) of the base material (BM) – steel 15Ch2NMFA after weld deposition of several layers by welding metal of Inconel FM 52. A temper bead welding (TBW) technique was used. Required microhardness up to 350 HV0.1 in heat affected zone of base material in distance 0.5 mm from fusion line was exceeded in all three experimental blocks with various welding energy inputs during deposition of three or five weld layers. Metallography showed reaustenitization and structure transformation in HAZ after the deposit of first layer in all three blocks. After deposit of the last layer the structure of HAZ in two blocks was tempered only and one variant of them have been recommended for futher technological tests. Structure of HAZ of the third block was not full tempered even after the last layer deposit.

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.

Sign in / Sign up

Export Citation Format

Share Document