Manual Self-Propagating High-Temperature Synthesis Welding of 45 Steel

2011 ◽  
Vol 189-193 ◽  
pp. 3484-3487
Author(s):  
Zhi Zun Li ◽  
Wen Tong Xin ◽  
Yong Sheng Wu ◽  
Li Feng Qu

A new style of emergency welding, named manual SHS welding ,was introduced. By this technique, metal materials could be welded on the condition of no electricity, no gas and no equipments. In this paper, the mechanism of manual SHS welding has been illustrated, the effect of thermit on welding and the microstructure of the welded joint have been studied, and the mechanical properties have been tested. Results showed that the combustion velocity of the combustion welding rod became higher when the content of (CuO+Al) thermit increased. The suitable (CuO+Al) content is 60%wt ~80%wt. The tested 45 steel plates were one-side welded with back formation. Microstructure analysis indicated that there are three zones in the welded joint, which are heat affected zone, fusion zone and weld metal. The weld metal and the 45 steel plates were combined metallurgically. The weld metal was copper based alloy. EDS patterns showed that there was diffusion of Cu, Fe and Ni in the three zones. The fracture of the weld joint is a typical ductile fracture. The tensile strength of the joints reached 400MPa and the impact absorbed energy was about 35J, which meet the requirement of mechanical properties for emergency welding. Manual SHS welding is an effective welding method for emergency maintenance in battlefield and outside field.

2018 ◽  
Vol 941 ◽  
pp. 224-229
Author(s):  
Takahiro Izumi ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Hiroaki Miyanaga

Microstructures and mechanical properties of lap fillet welded joints of several high and ultra-high tensile strength steel by arc welding were investigated. Steel plates having tensile strength of 400 (SPH400W), 590 (SPC590Y, SPC590R), 980 (SPC980Y) and 1500 MPa (SAC1500HP) class with 2 mm thickness were prepared. Four types of joints were formed by MAG welding; SPH400W/SPH400W, SPC590Y/SPC590Y, SPC980Y/SPC980Y and SAC1500HP/SPC590R. In joints with SPC590Y, SPC980Y and SAC1500HP steel which matrixes are martensitic microstructures, the HAZ softens due to transformation of martensite into ferrite with precipitating cementite. By using high and ultra-high tensile strength steel, the weld metal is strengthened due to dilution of the matrix into the weld metal and thus tensile shear strength of the welded joint increases. In the fatigue test, similar S-N diagrams were obtained in the all welded joints investigated. It seems that the effect of stress concentration due to the shape of the welded joint on fatigue properties is larger than that of the strength of the matrix.


2011 ◽  
Vol 391-392 ◽  
pp. 768-772 ◽  
Author(s):  
Li Yang ◽  
Zhan Zhe Zhang

The weldablity of dissimilar steel between 16MnR and S31803 was analyzed and researched. By means of optical microscope (OM), the microstructure of the weld joint was investigated, which is welded by tungsten inert gas arc backing welding (GTAW) and manual arc filling welding (SMAW). The mechanical properties and corrosion resistance of the welded joint was also tested and studied. Results indicate that austenite and acicular ferrite distribute uniformly in the weld metal, which strengths the toughness and ductility of the joint. The austenite content in weld is higher than that in over-heated zone of S31803.The SMAW joint structure is coarsening than that of GTAW and has more austenite content. It is also observed that there are a decarburization layer and a carbon-enriched zone nearby the fusion line. And very small amounts of the third phase of harmful metal phase are found in the fusion zone of S31803 side. The welded joint shows the excellent mechanical properties and corrosion resistance. The impact toughness of the weld metal is higher than in HAZ of 16MnR side, and the impact toughness at GTAW side and in HAZ is superior to the SMAW side.


2011 ◽  
Vol 197-198 ◽  
pp. 1658-1661
Author(s):  
Ying Xiong ◽  
Han Ying Zheng

Fatigue tests are carried out for 16MnR welded joint under constant strain control. Test results reveal that 16MnR weld metal exhibits characteristic of cyclic softening and non-masing obviously. The strain–life curve can be best described by the three-parameter equation. It shows the fatigue endurance limit in the heat-affecting zone (HAZ) of welded joint is lower than that in the weld metal.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1638 ◽  
Author(s):  
Shuwan Cui ◽  
Zhiyong Xian ◽  
Yonghua Shi ◽  
Baoyi Liao ◽  
Tao Zhu

In this paper, the microstructure and impact toughness of a S32101 duplex stainless steel underwater local-dry keyhole tungsten inert gas welded joint were studied. The impact toughness value of the underwater weld metal reached 78% of the onshore weld metal, which is in accordance with the underwater welding standards. The proportion of austenite in the underwater weld metal was 0.9% lower than that of the onshore weld metal. The proportion of the Σ3 coincidence site lattice boundaries and random phase boundaries in the underwater weld metal, which significantly influence the impact toughness of the weld metal, were smaller than that of the onshore weld metal.


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2233
Author(s):  
Tatyana Olshanskaya ◽  
Vladimir Belenkiy ◽  
Elena Fedoseeva ◽  
Elena Koleva ◽  
Dmitriy Trushnikov

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.


2016 ◽  
Vol 61 (4) ◽  
pp. 1771-1776 ◽  
Author(s):  
D. Hadryś

Abstract New technology of micro-jet welding could be regarded as a new way to improve mechanical properties of plug welds. The main purpose of that paper was analyzing of mechanical properties of plug welds made by MIG welding method with micro-jet cooling. The main way for it was comparison of plug welds made by MIG welding method with micro-jet cooling and plug welds made by ordinary MIG welding method. It is interesting for steel because higher amount of acicular ferrite (AF) in weld metal deposit (WMD) is obtained in MIG welding method with micro-jet cooling in relation to ordinary MIG welding method. This article presents the influence of the cooling medium and the number of micro-jet streams on mechanical properties of the welded joint. Mechanical properties were described by force which is necessary to destroy weld joint.


2015 ◽  
Vol 799-800 ◽  
pp. 377-381
Author(s):  
Mohd Amin Abd Majid ◽  
Muhammad Sarwar

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.


2015 ◽  
Vol 788 ◽  
pp. 259-266
Author(s):  
Yuriy N. Saraev ◽  
Valeriy P. Bezborodov ◽  
Evgenya A. Putilova

We have investigated the influence of the modes of adaptive pulse-arc welding and surfacing on the structure and physical-mechanical properties of welded joints of steel 09Mn2Si and the surfaced composition of this steel coated with a modified powder material of chromium carbide with the submicrocrystalline structure. It is shown that the pulsed mode of welding and surfacing can improve the homogeneity of the structure of the welded joint of steel and a surfaced coating and reduce the grain size of metals in both of them. Structural changes lead to an increase in ductility and toughness of the weld metal.


2015 ◽  
Vol 1089 ◽  
pp. 282-285
Author(s):  
Cheng Fan ◽  
Bao Lei Li ◽  
Dong Chen ◽  
Li Song

In this paper, on the basis of specimen model size mentioned in steel reinforced concrete coupling beam stress performance research, using the ANSYS finite element software about coupling beam specimens with different steel plates for one-off monotonic loading. Through the comparative analysis of simulation results, to explore the impact of different steel plate forms on concrete mechanical properties and ductility of coupling beams .


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