The influence of the technological cycle of production on the change in the physical and mechanical characteristics of bimetal with a butt welded joint in the cladding layer

2021 ◽  
Vol 87 (7) ◽  
pp. 59-66
Author(s):  
D. V. Nonyak ◽  
I. V. Denisov ◽  
О. L. Pervukhina
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Welded Joint ◽  
Butt Joint ◽  
Explosion Welding ◽  
Internal Stresses ◽  
Magnetic Memory ◽  
Cladding Layer ◽  
High Level ◽  
The Impact

The goal of the study is to consider the effect of explosion welding, heat treatment and cold straightening (gagging) in production of 09G2S + 08Kh13 bimetal with a butt welded joint in the cladding layer on the evolution of residual internal stresses. The impact of technological operations on the change in the level of residual stresses in a bimetallic material with a welded butt joint in the cladding layer was carried out using a non-destructive method of the magnetic memory of metals (MMM). This method is based on the use of the intrinsic stray magnetic field formed in the zones of increased dislocation density. The results revealed the special features of the location of zones with maximum values of the stress field gradient (dH/dx) and their evolution upon production of 09G2S + 08Kh13 bimetal with a butt welded joint in the cladding layer. An increase in the level of residual stresses in the cladding layer occurs after manual electric arc welding of 2 parts of the cladding layer made of 08Kh13 steel. It is shown that after explosion welding the level of residual stresses change. The stress relaxation occurs in the zone of weld in the cladding layer. At the same time, an increase in the level of residual stresses is observed in the main and cladding layer of the bimetal. To reduce the high level of residual stresses, we used the subsequent heat treatment of the obtained bimetallic samples in two different modes. The optimal heat treatment mode (heating to 720 ± 20°C, holding for 2 h, cooling with a furnace) which excluded the crack formation in the cladding layer upon mechanical straightening of bimetal was specified for 09G2S + 08Kh13 bimetal sample with a butt welded joint in the cladding layer.

scholarly journals Microscale residual stresses in additively manufactured stainless steel

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Wen Chen ◽  
Thomas Voisin ◽  
Yin Zhang ◽  
Jean-Baptiste Florien ◽  
Christopher M. Spadaccini ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Residual Stresses ◽  
Mechanical Behaviour ◽  
Work Hardening ◽  
Computational Modelling ◽  
Internal Stresses ◽  
X Ray Diffraction ◽  
Lattice Strains ◽  
The Impact

Abstract Additively manufactured (AM) metallic materials commonly possess substantial microscale internal stresses that manifest as intergranular and intragranular residual stresses. However, the impact of these residual stresses on the mechanical behaviour of AM materials remains unexplored. Here we combine in situ synchrotron X-ray diffraction experiments and computational modelling to quantify the lattice strains in different families of grains with specific orientations and associated intergranular residual stresses in an AM 316L stainless steel under uniaxial tension. We measure pronounced tension–compression asymmetries in yield strength and work hardening for as-printed stainless steel, and show they are associated with back stresses originating from heterogeneous dislocation distributions and resultant intragranular residual stresses. We further report that heat treatment relieves microscale residual stresses, thereby reducing the tension–compression asymmetries and altering work-hardening behaviour. This work establishes the mechanistic connections between the microscale residual stresses and mechanical behaviour of AM stainless steel.

Research about the Effect of Ultrasonic Impact on the Fatigue Life of Butt Weld Joint of 16MnR Steel

2011 ◽  
Vol 189-193 ◽  
pp. 3296-3299
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Huang Huang Yu ◽  
Jian Ping Shi
Keyword(s):  
Fatigue Life ◽  
Welded Joint ◽  
Butt Joint ◽  
Impact Machine ◽  
Ultrasonic Impact Treatment ◽  
Butt Weld ◽  
Impact Time ◽  
Weld Toe ◽  
The Impact ◽  
Fatigue Experiment

Surface treatment was carried out on the butt joint weldment of 16MnR steel by using the HJ-II-type ultrasonic impact machine. The ultrasonic impact current is 1.2A, the impact amplitude is 30 microns and ultrasonic impacting time is 30min and 60 min,respectively. Fatigue experiment was carried out for both treated specimen and un-treated specimen. The fatigue fracture observed with the scanning electron microscope of 6360LA type. The experimental results show that the fatigue life of the butt joint weldment of 16MnR steel can be significantly improved through the ultrasonic impact treatment. The main reason is that the ultrasonic impact can reduces the stress concentration in the weld toe, decrease the tensile stress, and even change to compressive stress in the weldment, the grain size in the welded joint can be refined. The longer the impact time, the greater increasing range of fatigue life will be. Compared to the sample without treatment, its fatigue life was increased 375.22%, 521.24%, respectively, when the impact time was 30, 60min, respectively.

scholarly journals Optimization of the Solidification Method of High-Level Waste for Increasing the Thermal Stability of the Magnesium Potassium Phosphate Compound

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3789
Author(s):  
Svetlana A. Kulikova ◽  
Sergey S. Danilov ◽  
Kseniya Yu. Belova ◽  
Anastasiya A. Rodionova ◽  
Sergey E. Vinokurov
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Compressive Strength ◽  
Potassium Phosphate ◽  
Treatment Temperature ◽  
High Level Waste ◽  
Leaching Rate ◽  
High Level ◽  
The Impact ◽  
Thermal Stability Of

The key task in the solidification of high-level waste (HLW) into a magnesium potassium phosphate (MPP) compound is the immobilization of mobile cesium isotopes, the activity of which provides the main contribution to the total HLW activity. In addition, the obtained compound containing heat-generating radionuclides can be significantly heated, which increases the necessity of its thermal stability. The current work is aimed at assessing the impact of various methodological approaches to HLW solidification on the thermal stability of the MPP compound, which is evaluated by the mechanical strength of the compound and its resistance to cesium leaching. High-salt surrogate HLW solution (S-HLW) used in the investigation was prepared for solidification by adding sorbents of various types binding at least 93% of 137Cs: ferrocyanide K-Ni (FKN), natural zeolite (NZ), synthetic zeolite Na-mordenite (MOR), and silicotungstic acid (STA). Prepared S-HLW was solidified into the MPP compound. Wollastonite (W) and NZ as fillers were added to the compound composition in the case of using FKN and STA, respectively. It was found that heat treatment up to 450 °C of the compound containing FKN and W (MPP-FKN-W) almost did not affect its compressive strength (about 12–19 МPa), and it led to a decrease of high compressive strength (40–50 MPa) of the compounds containing NZ, MOR, and STA (MPP-NZ, MPP-MOR, and MPP-STA-NZ, respectively) by an average of 2–3 times. It was shown that the differential leaching rate of 137Cs on the 28th day from MPP-FKN-W after heating to 250 °C was 5.3 × 10−6 g/(cm2∙day), however, at a higher temperature, it increased by 20 and more times. The differential leaching rate of 137Cs from MPP-NZ, MPP-MOR, and MPP-STA-NZ had values of (2.9–11) × 10−5 g/(cm2∙day), while the dependence on the heat treatment temperature of the compound was negligible.

Effect of Post Weld Heat Treatment on Weld Hardness Quality of P91 Welded Pipes

2015 ◽  
Vol 799-800 ◽  
pp. 377-381
Author(s):  
Mohd Amin Abd Majid ◽  
Muhammad Sarwar
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Residual Stresses ◽  
Weld Metal ◽  
Welded Joint ◽  
Post Weld Heat Treatment ◽  
Bead Geometry ◽  
Construction Sites ◽  
Weld Heat

Quality of a weld produced is generally evaluated by different parameters such as weld size, bead geometry, deposition rate, hardness and strength. A common problem that has been faced at the construction sites is to obtain a good welded joint having the required strength with minimal detrimental residual stresses to avoid any premature cracking due to high variation of hardness. In order to address this issue and to attain good weld quality, this study has been made to comprehend the effect of the post weld heat treatment on P91 material welds produced by TIG welding. Findings from the studies indicate that the PWHT has significant influence on the weld hardness of Alloy Steel-A335 P91 pipes. It is eminent that during cooling, after welding of P91, quenched martensite was formed in the HAZ that results in an increased hardness to an undesirable level of more than 250HB. PWHT at temperature of 760°C for 2 hours has good influence on mechanical properties as the hardness decreases and turns out to be uniformly distributed. If the PWHT is correctly carried out, the hardness of parent metals, heat affected zones and weld metal can be brought into the required limits to avoid any premature cracking due to high variation of hardness.

Examination of Coil Pipe Butt Joint Made of 7CrMoVTiB10-10(T24) Steel After Service

2012 ◽  
Vol 57 (2) ◽  
pp. 553-557 ◽  
Author(s):  
G. Golański ◽  
P. Gawień ◽  
J. Słania
Keyword(s):  
Heat Treatment ◽  
Grain Boundaries ◽  
Contact Area ◽  
High Stability ◽  
Welded Joint ◽  
High Hardness ◽  
Butt Joint ◽  
Post Weld Heat Treatment ◽  
Weld Heat

Examination of Coil Pipe Butt Joint Made of 7CrMoVTiB10-10(T24) Steel After Service The paper presents the results of examination of coil pipe butt joint made of 7CrMoVTiB10-10 steel (T24). Tested joint was in service for approximately 12 000 hours at the temperature of 540°C and pressure of 5.48MPa. Tests have revealed that the structure of all regions of the homogenous welded joint are correct and without any welding imperfections. Operation of the weld contributed mainly to advantaged precipitation of carbides especially on grain boundaries - frequently in the contact area of three grains' boundaries as well as in the form of continuous network of precipitates. The measurement showed high hardness of the weld, what indicates high stability of the microstructure. It makes possible to find that post-weld heat treatment is indispensable.

scholarly journals Narrow Gap MAG Welding and Joint Performance Analysis of 25Cr2NiMo1V Thick Plate

2022 ◽  
Vol 2160 (1) ◽  
pp. 012022
Author(s):  
Xiaoyan Qian ◽  
Xin Ye ◽  
Xiaoqi Hou ◽  
Fuxin Wang ◽  
Shaowei Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Ductile Fracture ◽  
Impact Energy ◽  
Welded Joint ◽  
Fusion Line ◽  
Coarse Grained ◽  
Mag Welding ◽  
Rotor Steel ◽  
Narrow Gap ◽  
The Impact

Abstract The narrow gap MAG welding system was used to successfully weld the 50mm thick butt joint of 25Cr2NiMo1V rotor steel. After 15-layer bead welding, heat treatment is performed on the welded joint. Compare the changes in the microstructure, tensile strength and impact energy of the welded joints and the heat-treated joints at 580°C (20h). The results show that after the heat treatment of the structure, the side lath ferrite in the coarse-grained region grows up, and the eutectoid ferrite grows up in the fine-grained region first. The strength of the welded joint is about 605MPa, and the fracture is characterized by ductile fracture. After heat treatment at 580°C (20h), the strength is about 543MPa, the fracture is characterized by ductile fracture, and there are also a large number of discontinuous small surface platforms, and the characteristic of brittle fracture appears slightly. The impact energy of the weld center of the welded joint is about 141J, the fusion line area is about 113J, and the toughness of the fusion line is slightly lower than that of the weld center. After heat treatment, the impact energy at the center of the weld is about 183J, the fusion line area is about 95J, the toughness of the weld center increases, and the toughness of the fusion line decreases.

scholarly journals Elucidating the Effect of Step Cooling Heat Treatment on the Properties of 2.25 Cr–1.0 Mo Steel Welded with a Combination of GMAW Techniques Incorporating Metal-Cored Wires

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6033
Author(s):  
Subhash Das ◽  
Jay Vora ◽  
Vivek Patel ◽  
Joel Anderrson ◽  
Danil Yurievich Pimenov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Weld Joint ◽  
Welded Joint ◽  
Gas Metal Arc Welding ◽  
Temper Embrittlement ◽  
Metal Arc Welding ◽  
Toughness Testing ◽  
Ductile To Brittle Transition ◽  
Cored Wires ◽  
The Impact

The prospect of using metal-cored wires instead of solid wires during gas metal arc welding (GMAW) of 2.25 Cr–1.0 Mo steels embraces several challenges. The in-service requirements for the equipment made up of these steels are stringent. The major challenge faced by the manufacturers is temper embrittlement. In the current study, the temper embrittlement susceptibility of the welded joint was ascertained by subjecting it to step cooling heat treatment. A 25 mm thick 2.25 Cr–1.0 Mo weld joint was prepared using a combination of the regulated metal deposition (RMD) and GMAW processes incorporating metal-cored wires. After welding the plates were exposed to post-weld heat treatment followed by a rigorous step cooling heat treatment prescribed by API standards. The temper embrittlement susceptibility of the weld joint was ascertained by Bruscato X-factor as well as by formulating ductile-to-brittle transition temperature (DBTT) curves by carrying out the impact toughness testing at various temperatures. Detailed microscopy and hardness studies were also carried out. It was established from the study that the X-factor value for the welded joint was 15.4. The DBTT for the weld joint was found to occur at −37 °C which was well below 10 °C. Optical microscopy and scanning electron microscopy indicated the presence of carbides and the energy dispersive X-ray spectrometry studies indicated the presence of chromium and manganese-rich carbides along with the presence of sulfur near the grain boundaries. This study establishes a base for the usage of metal-cored wires particularly in high temperature and pressure application of Cr–Mo steels.

Fatigue crack growth resistance of welded joints simulating the weld-repaired railway wheels metal

2017 ◽  
Vol 2 (86) ◽  
pp. 49-52 ◽  
Author(s):  
O.P. Ostash ◽  
V.V. Kulyk ◽  
V.D. Poznyakov ◽  
O.A. Haivorons’kyi ◽  
L.I. Markashova ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Residual Stresses ◽  
Weld Metal ◽  
Crack Growth ◽  
Welded Joint ◽  
Crack Growth Resistance ◽  
Fatigue Crack Growth Resistance ◽  
Railway Wheels

Purpose: The aim of the paper is to study the structure and fatigue crack growth resistance characteristics of weld metal (WM), and heat affected zone (HAZ) under cyclic loadings for the development of railway wheels weld-repairing technology. Design/methodology/approach: WM and HAZ of the welded joint were investigated. The welded joint of 65G steel (0.65 mass.% C; 0.19 Si; 0,91 Mn), which is a model material for high-strength railway wheels, was received by welding Sv-08HM wire per linear welding energy of 10 kJ/cm. Regimes of welding were selected so that the cooling rate of the metal in the temperature range 500-600°C was 5°C/s. As a result, the bainite structure in WM and bainite-martensite one in HAZ are formed. To eliminate the residual stresses generated after the weld cooling, heat treatment was proposed: holding at 100°C for 2 hour after cooling under temperature below then that at the beginning of martensite transformation. Fracture resistance under cyclic loading was estimated by fatigue crack growth rates diagrams (da/dN vs. ΔK) according to standard method for compact tension samples testing. The microstructure and fracture surface were investigated using an optical, and electronic scanning and transmission microscope. Findings: Microstructure parameters and fatigue crack growth resistance characteristics of WM and HAZ after the proposed heat treatment, and also residual stresses of the second kind and local strains in the bulk of bainite and martensite are obtained. Research limitations/implications: Investigations were conducted on samples that simulate the structure and properties of real renovated railway wheels made of steel with high content (0.65%) of carbon. Practical implications: Service durability and safety of weld-repaired railway wheels under high service loadings is increased. Originality/value: HAZ is the most dangerous zone in terms of fatigue cracks initiation and propagation in elements repaired by surfacing method. The positive result on the proposed heat treatment influence is received since the fatigue crack growth resistance characteristics of HAZ metal with bainite-martensite structure raise to the level of weld metal.

Research about the Effect of Ultrasonic Impact on the Mechanical Property of Welded Butt Joint of P355NL1 Steel

2014 ◽  
Vol 644-650 ◽  
pp. 4752-4755
Author(s):  
Ying Xia Yu ◽  
Bo Lin He ◽  
Zhi Jun Zhang ◽  
Jian Ping Shi
Keyword(s):  
Mechanical Property ◽  
Residual Stress ◽  
Compressive Residual Stress ◽  
Welded Joint ◽  
Butt Joint ◽  
Impact Machine ◽  
Ultrasonic Impact Treatment ◽  
Weld Toe ◽  
The Impact ◽  
Scanning Electron

Surface treatment was carried out on the butt joint weldment of P355NL1 steel by using the HJ-II-type ultrasonic impact machine. The ultrasonic impact current is 1.5A, the impact amplitude is 20 microns and ultrasonic impacting time is 5min. Tensile test was carried out for both treated specimen and un-treated specimen. The fracture observed with the scanning electron microscope of 6360LA type. The experimental results show that although the compressive residual stress can be obtained in the surface of weld toe area, and the grain size in the welded joint can be refined, but the mechanical property of the butt joint of P355NL1 steel can not be improved through the ultrasonic impact treatment. The main reason is that the ultrasonic impact layer is only 120um, it is to thin to compared to the thickness of the specimen.

Impact of Heat Treatment on the Structure and Properties of the QE22 Alloy Welded Joints

2012 ◽  
Vol 191 ◽  
pp. 183-188
Author(s):  
Agata Kierzek ◽  
Janusz Adamiec
Keyword(s):  
Heat Treatment ◽  
Welded Joints ◽  
Creep Resistance ◽  
Welded Joint ◽  
Casting Process ◽  
Structure And Properties ◽  
Cast Magnesium Alloy ◽  
The One ◽  
Cast Magnesium ◽  
The Impact

The QE22 cast magnesium alloy containing silver, rare earth elements and zirconium is characterized by high mechanical properties and creep resistance of up to 200 ° C. It is cast gravitationally into sand moulds and permanent moulds. After the casting process any possible defects appearing in the cast are repaired with the application of welding techniques. The repaired cast should possess at least the same properties as the one which does not require any repairs. The aim of this thesis was to determine the impact of the heat treatment on the microstructure of the QE22 alloy welded joint. The creep resistance of the welded joints was also analyzed.

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