Friction stir welding of mild steel to alloy 625 – development of welding parameters

Friction stir welding parameters were developed for a 6 mm thick dissimilar butt joint made of mild steel and Ni based alloy 625. A composite W-Re/polycrystalline cubic born nitride tool was used to study the effect of tool offset (between 0 and 3·13 mm away from the alloy 625 plate) and rotational speed (between 250 and 350 rev min^?1) on joint consolidation. When non-optimal parameters were used, macrovoids were observed at the advancing side and faying surface near the joint interface root. Defect free joints were obtained using 300 rev min^?1, 100 mm min^?1, tool offset of 1·63 mm, and axial force between 25 and 30 kN, under force controlled mode.     

Development of welding technique for petrochemical industry in China

ＤｅｖｅｌｏｐｍｅｎｔｏｆｗｅｌｄｉｎｇｔｅｃｈｎｉｑｕｅｆｏｒｐｅｔｒｏｃｈｅｍｉｃａｌｉｎｄｕｓｔｒｙｉｎＣｈｉｎａ￥ＬＩＱｉｎｇｌｉｎ（Ｓｉｎｏ－ＰｅｔｒｏｃｈｅｍｉｃａｌＣｏｒｐｏｒａｔｉｏｎ，Ｂｅｉｊｉｎｇ（１０００２９）ＺＨＯＵＺｈｅｎｄ...     

Development and application of flux‐paste for laser welding of aluminium alloys

Summary

A metal which rejects energy or diffuses it too easily results in an energy surplus, modifying the balance of the usual mechanisms of laser welding. The solution is to stabilise the molten pool in order to avoid such losses.     

Design and development of automatic systems for assembly welding muffler of Santana automobile

ＤｅｓｉｇｎａｎｄｄｅｖｅｌｏｐｍｅｎｔｏｆａｕｔｏｍａｔｉｃｓｙｓｔｅｍｓｆｏｒａｓｓｅｍｂｌｙｗｅｌｄｉｎｇｍｕｆｆｌｅｒｏｆＳａｎｔａｎａａｕｔｏｍｏｂｉｌｅＨＥＤｅｆｕ；ＹＵｈａｉｌｉａｎｇ；ＴＡＮＧＸｉｎｈｕａ；ＷＡＮＧＳｉｚｕｏａｎｄＺｈ...     

Development of torch position control and welding condition control technology for all‐position,multi‐layer GTA welding. Development of fully automatic GTA welding system for pipes (2nd Report)

In pulsed TIG welding, the current varies between two well-defined energy levels in a given frequency, thus being necessary to regulate a set of variables consisting of the peak current, peak time, background current, background time and the welding speed. Yet despite being a widespread technique, in practice, these welding variables are often regulated arbitrarily. This can lead to inefficient use of the pulsed current regarding the end result of the weld and aspects of productivity. This paper aims to present a roadmap developed in order to meet the practical need to establish criteria to assist in the determination of pulsed TIG welding variables, taking as its premise the desired width of the weld bead, overlap between the weld points comprising the weld bead and the welding speed. Finally, one application of this roadmap is presented in bead on plate welding of stainless steel plates with 1.2-mm thickness.     

Development of an engineering－practical expert system for arc welding and its shell

Ｄｅｖｅｌｏｐｍｅｎｔｏｆａｎｅｎｇｉｎｅｅｒｉｎｇ－ｐｒａｃｔｉｃａｌｅｘｐｅｒｔｓｙｓｔｅｍｆｏｒａｒｃｗｅｌｄｉｎｇａｎｄｉｔｓｓｈｅｌｌＰｅｎｇＪｉｎｎｉｎｇ；ＣｈｅｎＢｉｎｇｓｅｎａｎｄＬｉｕＱｉａｎｇ（ＱｉｎｇｈｕａＵｎｉｖｅｒｓｉｔｙ，...     

Investigation of welding procedure of 9Cr－1Mo steel for manufacturing petrochemical equipment

Ｉｎｖｅｓｔｉｇａｔｉｏｎｏｆｗｅｌｄｉｎｇｐｒｏｃｅｄｕｒｅｏｆ９Ｃｒ－１Ｍｏｓｔｅｅｌｆｏｒｍａｎｕｆａｃｔｕｒｉｎｇｐｅｔｒｏｃｈｅｍｉｃａｌｅｑｕｉｐｍｅｎｔ￥ＨｕａｎｇＹｕｎｑｉｎｇａｎｄＣｈｅｎＢｏｌｉ（ＴｓｉｎｇｈｕａＵｎｉｖｅｒｓｉｔ...     

Development of Trivex friction stir welding tool Part 1 – two-dimensional flow modelling and experimental validation

Abstract

This paper describes the application of the computational fluid dynamics (CFD) code, FLUENT, to modelling the metal flow in friction stir welding (FSW). Through the use of a novel slip model, a two-dimensional pin profile was optimised to minimise the traversing force. Two versions of a tool based on the optimised profile were developed: the plain 'Trivex' and the threaded 'MX-Trivex'. These were tested against one version of the 'MX-Triflute' tool that had comparable pin and shoulder diameters. Experiments showed that the traversing force was reduced by between 18 and 25% and the down force was reduced by approximately 12% when compared with the MX-Triflute tool. The different pin designs had little effect on the heat input and the tensile strengths of the welds were comparable. The development and validation of the full three-dimensional model for both the Trivex and Triflute tools is described in Part 2.     

Composition and microstructure characteristics in bond area of TIG welding for high strength ZA alloy

1　ＩＮＴＲＯＤＵＣＴＩＯＮＺＡａｌｌｏｙｉｓｆｉｒｓｔｌｙｕｓｅｄａｓｔｈｅｓｕｂｓｔｉｔｕｔｅｏｆｂｒｏｎｚｅａｎｄｂａｂｂｉｔａｌｌｏｙｉｎ 196 0ｓ .Ｗｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆｓｃｉ ｅｎｃｅａｎｄｔｅｃｈｎｏｌｏｇｙ ,ｍａｎｙｎｅｗＺＡａｌｌｏｙｓｈａｖｅｂｅｅｎｄｅ ｖｅｌｏｐｅｄｉｎｒｅｃｅｎｔｙｅａｒｓ[1] .Ｔｈｅｙａｒｅｗｉｄｅｌｙｕｓｅｄｉｎｓｕｃｈｉｎｄｕｓｔｒｉａｌｆｉｅｌｄｓａｓｍｅｃｈａｎｉｃａｌ,ｉｎｓｔｒｕｍｅｎｔ ,ｌｉｇｈｔｉｎｄｕｓ ｔｒｙ ,ｅｌｅｃｔｒ…     

Development of materials database system for cae system of heat treatment based on data mining technology

Computer simulation for materials processing needs of materials. In order to employ the accumulated large data on a huge database containing a great deal of various physical properties materials heat treatment in the past years, it is significant to develop an intelligent database system. Based on the data mining technology for data analysis, an intelligent database web tool system of computer simulation for heat treatment process named as IndBASEweb-HT was built up. The architecture and the arithmetic of this system as well as its application were introduced.     

Evaluation of repair welding procedures for 2.25Cr–1Mo and 9Cr–1Mo steel welds

Abstract

Chromium–molybdenum steels are extensively used in the steam generator circuits of power plants. These components may require welding of the cracks that can develop during fabrication, storage, and transportation stages, or during the service life of the plant. This investigation compares repair welding methods for Cr–Mo steels, using 2.25Cr–1Mo and 9Cr–1Mo materials. To simulate aging during service, welds were heat treated at 873 K for 5000 h. Simulated repair welding of the aged welds was carried out at the weld/base metal interface, i.e. at the location at which cracks are usually reported to occur during service. Two repair welding methods (half bead and butter bead temper bead methods) conforming to the ASME Boiler and Pressure Vessel Code were used. Tensile properties, hardness profiles, and X-ray diffraction based residual stress distributions were determined for both the Cr–Mo steel welds to evaluate the simulated repair welds. Analysis of the test results showed that both the repair welding methods can be used for 2.25Cr–1Mo steel welds, although the butter bead temper bead method is much more suitable for both the 2.25Cr–1Mo and 9Cr–1Mo steel welds.     

Microstructure and mechanical properties of butt joints of QCr0.8／1Cr21NiSTi equal-thickness dissimilar materials by electron beam welding

Butt joints of QCrO. 8/1Cr2lNiSTi equal-thickness dissimilar materials were obtained by electron beam welding with fixed accelerating voltage 60 kV and focus current 1.99 A, changed electron beam current and welding velocity. Microstructure and composition of the EBW joint were investigated by means of optical micrography and EDX analysis, mechanical properties of the joint were also tested. The results show that joint‘ s macrostructure was divided into three zones : top weld zone near QCrO. 8 and bottom weld zone consisting of Cu (ss. Fe ) with a certain amount of dispersedly distributed (α ε) mixed microstructure , middle weld zone consisting of (α ε ) microstracture with a small amount of Cu (ss. Fe )particles. Morphological inhomogeneous macrostructure and uneven chemical compostion of QCrO. 8/1Cr21NiSTi joint by EBW are the most important factor to result in decreasing joining strength.     

Microstructure and mechanical properties of butt joints of QCr0.8/1Cr21Ni5Ti equal-thickness dissimilar materials by electron beam welding

0　IntroductionThedissimilarmaterialsjointisusuallyemployedinindustrialproductiontomakefulluseofthematerialsperformanceadvantageorspecialstructuralpurpose.Thedissimilarmaterialsjoiningtechnologybetweencopperalloyandstainlesssteelhasattractedagreatdealofattention,botheffectiveassemblageputweldedcomponent’scoolingandhighstrengthintoeffect.However,becauseofbothmaterialschemicalandthermophysicalperformancedifferenceandcomplexityofweldingmetallurgy,thedefectsuchaspore,crackandbrittlephaseandarathe…