Fatigue Properties of AF1410 Steel Welded Joint by Electron Beam Welding

Fatigue test of AF1410 steel and two thickness of electron beam have been done, and fatigue properties of the base metal and EB-welded joints have been studied. The results showed that fatigue limit of electron beam welded joints was close to that of base metal under this test conditions, and the welded thickness has little effect on S-N curves of electron beam welded samples under this test conditions. From SEM fracture morphology, it can be seen that fracture morphology of the welded samples was not obvious different form base metal. In the instant-off area of electron beam welded sample, there was dimple-like morphology showing good ductility.

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Application of Dynamic Beam Positioning for Creating Specified Structures and Properties of Welded Joints in Electron-Beam Welding

Materials ◽

10.3390/ma13102233 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2233

Author(s):

Tatyana Olshanskaya ◽

Vladimir Belenkiy ◽

Elena Fedoseeva ◽

Elena Koleva ◽

Dmitriy Trushnikov

Keyword(s):

Mechanical Properties ◽

Electron Beam ◽

Weld Metal ◽

Thermal Effect ◽

Welded Joints ◽

Electron Beam Welding ◽

Welded Joint ◽

Parent Metal ◽

Cooling Rates ◽

Structures And Properties

The application of electron beam sweep makes it possible to carry out multifocal and multi-beam welding, as well as combine the welding process with local heating or subsequent heat treatment, which is important when preparing products from thermally-hardened materials. This paper presents a method of electron beam welding (EBW) with dynamic beam positioning and its experimental-calculation results regarding the formation of structures and properties of heat-resistant steel welded joints (grade of steel 20Cr3MoWV). The application of electron beam oscillations in welding makes it possible to change the shape and dimensions of welding pool. It also affects the crystallization and formation of a primary structure. It has been established that EBW with dynamic beam positioning increases the weld metal residence time and the thermal effect zone above the critical A3 point, increases cooling time and considerably reduces instantaneous cooling rates as compared to welding without beam sweep. Also, the difference between cooling rates in the depth of a welded joint considerably reduces the degree of structural non-uniformity. A bainitic–martensitic structure is formed in the weld metal and the thermal effect zone throughout the whole depth of fusion. As a result of this structure, the level of mechanical properties of a welded joint produced from EBW with dynamic electron beam positioning approaches that of parent metal to a greater extent than in the case of welding by a static beam. As a consequence, welding of heat-resistant steels reduces the degree of non-uniformity of mechanical properties in the depth of welded joints, as well as decreases the level of hardening of a welded joint in relation to parent metal.

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Ti–6Al–4V welded joints via electron beam welding: Microstructure, fatigue properties, and fracture behavior

Materials Science and Engineering A ◽

10.1016/j.msea.2013.12.089 ◽

2014 ◽

Vol 597 ◽

pp. 225-231 ◽

Cited By ~ 21

Author(s):

Xiaoguang Yang ◽

Shaolin Li ◽

Hongyu Qi

Keyword(s):

Electron Beam ◽

Welded Joints ◽

Fracture Behavior ◽

Electron Beam Welding ◽

Fatigue Properties

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Influence of Welded Pores on Very Long-Life Fatigue Failure of the Electron Beam Welding Joint of TC17 Titanium Alloy

Materials ◽

10.3390/ma12111825 ◽

2019 ◽

Vol 12 (11) ◽

pp. 1825 ◽

Cited By ~ 4

Author(s):

Fulin Liu ◽

Hong Zhang ◽

Hanqing Liu ◽

Yao Chen ◽

Khan Muhammad Kashif ◽

...

Keyword(s):

Titanium Alloy ◽

Electron Beam ◽

Fatigue Life ◽

Base Metal ◽

Fatigue Failure ◽

Electron Beam Welding ◽

Welded Joint ◽

Fatigue Cracks ◽

Failure Behavior ◽

Long Life

The electron beam welding process is widely used in the connection among titanium alloy material parts of aero-engines. Its mechanical properties need to meet the requirements of long life and high reliability. In this paper, the static strength and the fatigue failure behavior of the electron beam weldments of TC17 titanium alloy were investigated experimentally under low amplitude high frequency (20 kHz), and the mechanical response and failure mechanism under different external loading conditions were analyzed. In summary, the samples were found to have anisotropic microstructure. The tensile strength of the PWHT of TC17 EBW joint was ~4.5% lower than that of the base metal. Meanwhile, compared with the base metal, the fatigue strength was reduced by 45.5% at 109 cycles of fatigue life. The fracture analysis showed that the fatigue failure of the welded joint of TC17 alloy was caused by the welded pores and the fatigue cracks initiated from the welded pores. A fine granular area (FGA) was observed around the crack initiation region. The existence of pores caused the stress intensity factor of the fine granular area (KFGA) to be inversely proportional to the fatigue life. The KFGA calculation formula was modified and the fatigue crack propagation threshold of the welded joint of TC17 alloy was calculated (3.62 MPa·m1/2). Moreover, the influences of the effective size and the relative depth of the pores on the very long fatigue life of the electron beam welded joint of TC17 titanium alloy were discussed.

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Electron Beam Welding of Ti-24Al-17Nb-0.5Mo Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.821 ◽

2005 ◽

Vol 475-479 ◽

pp. 821-824

Author(s):

J.Y. Zou ◽

Yu You Cui ◽

Rui Yang

Keyword(s):

Electron Beam ◽

Base Metal ◽

Room Temperature ◽

Electron Beam Welding ◽

Welded Joint ◽

Weld Zone ◽

Welding Parameters ◽

Eb Welding ◽

Phase Combination ◽

Postweld Heat

Electron beam (EB) welding of Ti-24Al-17Nb-0.5Mo (at.%) alloy and the effects of postweld heat treatments (PWHT) were studied. Through optimizing the welding parameters, defect-free welding joint was obtained. For the as-welded joint, the fusion zone (FZ) consisted of predominant β and occasional α2 within β grains. Microhardness of FZ was higher than that of the base metal (BM) and that of the heat affected zone (HAZ) was between that of BM and FZ. PWHTs greatly modified the microstructures and mechanical properties of the weld zone. PWHTs at both 820oC and 900oC yielded fine acicular laths in FZ leading to severe brittleness of the weld. Appropriate microstructures and phase combination were obtained by PWHT at 1000oC for 2 h, and room-temperature tensile strength reached the value of the base metal after the same thermal cycle.

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Influence of the welding parameters on the weld metal mechanical heterogeneity of EP517 (Fe12Cr2NiMoWVNb) steel and 36NKhTYu (Fe36Ni12Cr3TiAl) alloy dissimilar welded joints

Journal of Physics Conference Series ◽

10.1088/1742-6596/2077/1/012001 ◽

2021 ◽

Vol 2077 (1) ◽

pp. 012001

Author(s):

K T Borodavkina ◽

E V Terentyev ◽

A P Sliva ◽

A Yu Marchenkov ◽

I E Zhmurko ◽

...

Keyword(s):

Electron Beam ◽

Standard Deviation ◽

Weld Metal ◽

Welded Joints ◽

Electron Beam Welding ◽

Welded Joint ◽

Welding Parameters ◽

Mechanical Heterogeneity ◽

Alloy 36Nkhtyu ◽

Hardness Values

Abstract The article presents the results of assessing the effect of the welding speed and the displacement of the electron beam relative to the joint on the mechanical heterogeneity of the weld metal of dissimilar welded joints of EP517 (Fe12Cr2NiMoWVNb) steel and 36NKhTYu (Fe36Ni12Cr3TiAl) alloy. Aging curves are plotted for the weld metal of welded joints made at electron beam welding (EBW) speeds of 30 m/h and 120 m/h, as well as for the weld metal of the welded joint made at a speed of 30 m/h with various electron beam displacements. An assessment of the change in the mechanical heterogeneity of the weld metal was carried out by the change in the standard deviation of the hardness values, and metallographic studies were also carried out. It was found that a decrease in the EBW speed leads to a decrease in the standard deviation of the results of measuring the hardness of the weld metal after aging from 45 to 14 HV5 or from 18% to 6%. It was also found that an increase in the displacement of the electron beam to alloy 36NKhTYu (Fe36Ni12Cr3TiAl) to 60% leads to an increase in the hardness of the weld metal from 225 to 305 HV5 (by 35%).

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Microstructure and mechanical properties of 9Cr-3W-3Co steel welded joints by vacuum electron beam welding

International Journal of Modern Physics B ◽

10.1142/s0217979221501927 ◽

2021 ◽

pp. 2150192

Author(s):

Youyi Zhang ◽

Guoqing Gou

Keyword(s):

Mechanical Properties ◽

Electron Beam ◽

High Temperature ◽

Base Metal ◽

Welded Joints ◽

Electron Beam Welding ◽

Lath Martensite ◽

Weld Zone ◽

Creep Fracture ◽

Welding Joints

This paper aims to explore the microstructure and mechanical properties of 9Cr-3W-3Co steel welded joints. In the experiment, 9Cr-3W-3Co steel samples were welded by vacuum electron beam welding technology (VEBW) without any metal stuff, and all the welding joints were treated by high-temperature tempering at [Formula: see text]C for 8 h. The microstructure of welding joints was observed by OM, SEM and TEM; and the mechanical properties of welded joints were analyzed by microhardness test, room-temperature tensile, test impact test and high-temperature creep test. As a result, all the 9Cr-3W-3Co steel samples displayed the microstructure status as martensite under the Scheffler-Schneider prediction model, which conformed to the expectation. After high-temperature tempering, the grains of the welding zone were smaller than the base metal and the composition was tempered lath martensite only. Some of the lath martensite bundles even showed the incomplete polygonal transformation. The M[Formula: see text]C6 carbides and MX phase were distributed continuously along with the lath martensite interfaces, which showed a tendency for further aggregation. The microhardness of the weld zone was slightly higher than the base metal (mean of base metal: 240 HV[Formula: see text], mean of weld zone: 273 HV[Formula: see text] and mean of heat affected area: 274 HV[Formula: see text]. There was no softening phenomenon observed, and the welding joints maintaining the high intensity. Other mechanical properties like the tensile strength (mean: 750 MPa), yield strength (mean: 707 MPa) and impact toughness (mean of WM: 25.1 J and HAZ: 23.3 J) were also excellent. When the temperature parameter is constant, the time for creep fracture reduces significantly with the increase of the stress; whereas the time for creep fracture decreases significantly as the temperature increases, while the stress parameter is constant.

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