Roll Welding Research Articles

Role of Welding in Structural Steel Intensive Construction in India

Construction builds the basic framework and infrastructure of a country, which stimulates further economic, commercial and industrial activities. In building construction role of steel is same as that of bones in a living being.

From the Editor's Desk

During the last decade the steel industry in the country in general has carried on an intensive campaign tor increasing the use of steel in large urban conventional fabrication sectors and also in the under utilized rural sector. Considerable disparity in steel consumption exists between the developed and developing countries as described in the paper "Role of Welding in Structural Steel Intensive Construction in India" by Dr. S. R. Mediratta, et ai of the Institute of Steel Development & Growth (ISDG), Kolkata. The paper has discussed the various uses of steel, dependence of the welding sector on increasing consumption of steel, the importance of welding technology and the growth possibilities of the welding sector - otherwise can one imagine a return to the days of riveted construction? Welded fabrication in steel today is changing the face of urban life. The paper also points to some of the problems facing the fabrication industry like the situation regarding specific steel supply, and also to inadequate demand development in the rural sector.

Morphology and microstructure of Alp/SiCp composite powder prepared using a stone mill

Aluminium based metal matrix composite powder was prepared using a stone mill. Elemental powders of pure aluminium and SiC particle reinforcement were milled in a horizontal stone mill at a constant rotation. Two different mill gaps were employed to investigate the distribution of SiC particles embedded in the aluminium matrix. In each case, 1 ton h-1 of Alp/SiCp composite powder was produced. The shape of the aluminium particles changed from ligamental to spherical and the angular faceted SiC particles became more spherical in form. Morphological and microstructural observations revealed that the advantages of using a stone mill to produce composite powder were that it provided well distributed SiC particles and good bonding between matrix and reinforcement. The mixing mechanism of the stone mill can be described as follows: shear deformation of aluminium particles and embedding of the SiC into the aluminium flakes, rolling and cold welding of the Al/SiC composite flakes to form rolls, and fracture of the composite rolls into spherical particles. Hot extrusion improved the distribution of the SiC particles in the matrix.

Growth rate of intermetallic compounds in Al/Cu bimetal produced by cold roll welding process

The aim of this article is to study the growth rate of intermetallic compounds at the interface of cold roll bonded Al/Cu bimetal at 250°C and compare the results with a similar study performed on friction welding of Al to Cu. Samples of tri-layered Cu–Al–Cu composite were produced by the cold roll welding process and heat treated at constant temperature of 250°C for 1 to 1000 h. The thickness, morphology and composition of the intermetallic compound at the interface of Cu and Al were studied by optical and scanning electron microscope and EDX analyzer. The presence of various intermetallic compounds (Cu 3Al, Cu 4Al 3, CuAl and CuAl 2) was detected and the priority of formation of each compound was studied. The bond strength and electrical resistivity of different samples were measured by peeling test and a high precision micro-ohmmeter, respectively. The variations of resistivity and bond strength versus thickness of intermetallic compound were plotted. It was observed that the strength and electrical conductivity are greatly reduced by increasing the thickness of intermetallic compounds. Moreover, the growth rate of intermetallic compounds in roll welded bimetal composite is lower compared with that reported for similar friction welded specimens.

Production of NbTi CICC's for SST-1 project at IPR

A total of 24 pieces of NbTi CICC with outer dimension of 14.8 mm/spl times/14.8 mm and a piece length of 600 m each have been successfully fabricated for building TF and PF coils. The CICC is made through the roll forming and welding process. The insert cable with a scheme of 3/spl times/3/spl times/3/spl times/5 is made from 0.86 mm diameter multifilamentary NbTi/Cu strand with 10 /spl mu/m diameter NbTi filaments embedded in Cu matrix at a Cu ratio of 4.9. No treatment is applied to the strand surface. A 0.025 mm thick SS304 tape is wrapped on the finished fourth stage cable. A 15 mm thick SS304L strip is then roll formed around the wrapped fourth stage cable and TIG welding 6 applied continuously at the top longitudinal seam. The welded conduit is finished to the final square dimension, by passing it through sizing rolls and turks head rolls set at the end of the jacketing line. The critical current for a CICC, estimated through multiplying an average I/sub c/ (without self-field correction) for the 10 extracted strands by the number of strands of 135 in a CICC, is approximately 38 kA at 5 T, 4.2 K. This means that there is: no significant degradation of I/sub c/'s for the strands due to the cabling and jacketing process. It is confirmed that the finished CICC pieces of 600 m each show a He leakage level well below 0.2/spl times/10/sup -3/ Toll 1/s.

Role of Welding in Structural Steel Intensive Construction in India

Construction builds the basic framework and infrastructure of a country, which stimulates further economic, commercial and industrial activities. In building construction role of steel is the same as that of bones in a living being.

Explosion of a combustion chamber shell

This paper describes an investigation of the explosion of a combustion chamber shell in an aeroengine. Metallographic analysis, mechanical calculation and fatigue life estimation have been performed to determine failure causes and to make a proposal for preventive measure. The analytical results show that the poor quality of the roll welding seam is the fundamental cause of failure added to which a crack in the seam had not been discovered during a second overhaul. The effective design improvement is argon arc welding instead of roll welding in fabricating new shells. The effective preventive measures for old shells are to raise the strength of the seam by additional melt welding at overhaul, and to perform rigorous nondestruction inspection.

Role of Welding in Hydroelectric Power Generation

Role of Welding in Hydroelectric Power Generation

Role of Welding in the Process Plants Petrochemical Industry

Role of Welding in the Process Plants Petrochemical Industry

The role of welding in component integrity: Cerjak, H.H. Proc. High Temperature Materials for Powder Engineering 1990, I, Liege, Belgium (Kluwer, Dordrecht, The Netherlands, 1990) pp. 445–472

The role of welding in component integrity: Cerjak, H.H. Proc. High Temperature Materials for Powder Engineering 1990, I, Liege, Belgium (Kluwer, Dordrecht, The Netherlands, 1990) pp. 445–472

冷間圧接による金属クラッド薄板の製造方法と接着機構

冷間圧接による金属クラッド薄板の製造方法と接着機構

Thermodynamic analysis of the processes taking place in gaps of multi-layer hermetic packets during roll welding

Thermodynamic analysis of the processes taking place in gaps of multi-layer hermetic packets during roll welding