Welding Problems in Shipbuilding

1969 ◽  
Vol 6 (01) ◽  
pp. 66-75
Author(s):  
Koichi Masubuch
Keyword(s):  
Arc Welding ◽  
State Of The Art ◽  
Welding Process ◽  
Shipbuilding Industry ◽  
Technical Problems ◽  
Metal Structures ◽  
The Past ◽  
Manual Arc Welding ◽  
Arc Welding Process ◽  
Welding Processes

During the past 30 years, many new welding processes have been applied to the fabrication of various metal structures. However, these processes have largely been ignored by the shipbuilding industry, and modern ships continue to be fabricated primarily by a manual arc-welding process that is more than fifty years old. This paper discusses some of the problems related to welding ship structures, focusing mainly upon two important subject areas:new welding processes, andnotch toughness of weld metal. The author reviews briefly developments in the technology and, emphasizing the technical problems, indicates how research can improve the state of the art.

The Determination of Noxes Emissions in Case of Manual Arc Welding Process with Coated Electrode

2018 ◽  
Vol 69 (7) ◽  
pp. 1826-1829
Author(s):  
Claudiu Babis ◽  
Augustin Semenescu ◽  
Oana Roxana Chivu ◽  
Maria Alina Gligor ◽  
Gabriel Iacobescu ◽  
...  
Keyword(s):  
Production System ◽  
Arc Welding ◽  
Welding Process ◽  
Practical Method ◽  
Machine Building ◽  
Short Exposure ◽  
Metal Bath ◽  
Coated Electrode ◽  
Manual Arc Welding ◽  
Arc Welding Process

The occupational risk assessment of a machine building company must cover each activity and workstation, taking into account each component of the production system (work system), each workload, work equipment and the work environment. This assessment is an extremely complicated and complex issue since the production system of such an enterprise is particularly complex and complicated. Welding assembly is a highly polluting technology process, especially of the atmosphere and soil. The formation of gases in the welding process is the result of burning of the electrodes, powders, forming the molten metal bath and making the weld seam. Welding operators are exposed to smoke and toxic gases resulting from the welding process, which can in many cases be hazardous to health. Many acute intoxications that may be caused by excessive exposure to or short exposure to smoke and gas resulting from the welding process have been studied over time. In the paper are presented the elements of risk related to the welding process and the most widespread occupational diseases that can occur in the ranges of the welding operators. The following are presented the noxious emissions from welding and are determined by a practical method the emission of noxious at welding deposition of a welding sample, using the manual arc welding process with coated electrode.

Optimization of Flux Cored Arc Welding Process Parameter Using Genetic and Memetic Algorithms

2013 ◽  
Vol 13 (4) ◽  
pp. 239-250 ◽  
Author(s):  
T. Kannan ◽  
N. Murugan ◽  
B. N. Sreeharan
Keyword(s):  
Arc Welding ◽  
Welding Process ◽  
Memetic Algorithms ◽  
Optimization Techniques ◽  
Low Carbon ◽  
Robotic Welding ◽  
Bead Width ◽  
Flux Cored Arc Welding ◽  
Arc Welding Process ◽  
Welding Processes

AbstractMost of the manufacturing enterprises indulge in the bonding of metals during the production process. This makes welding one of the most important processes in industries. Subsequently, due to the high usage of welding process, industrial engineers desire to optimize the parameters concerned to achieve the desired weld bead characteristics. This paper focuses on optimization of flux cored arc welding process parameters, which are used for deposition of duplex stainless steel on low carbon structural steel plates. Experiments were conducted based on central composite rotatable design and mathematical models were developed using multiple regression method. Further, optimization with objectives as minimizing percentage dilution, maximizing height of reinforcement and bead width was carried out using genetic algorithm and memetic algorithm. This problem was formulated as a multi objective, multivariable and non-linear programming problem. The algorithms were implemented using basic functions of C language making it highly reliable, adoptable, very user friendly and extendable to other welding processes such as GMAW, GTAW, robotic welding, etc. The adopted optimization techniques were further compared based on various computational factors.

scholarly journals Characteristics of Welding and Arc Pressure in the Plasma–TIG Hybrid Welding Process

2018 ◽  
Author(s):  
Bo Wang ◽  
Xunming Zhu ◽  
Hongchang Zhang ◽  
Hongtao Zhang ◽  
Jicai Feng
Keyword(s):  
Arc Welding ◽  
Gas Flow ◽  
Welding Process ◽  
Hybrid Welding ◽  
Plasma Arc ◽  
Arc Pressure ◽  
Arc Current ◽  
Arc Welding Process ◽  
Welding Processes

In this article, a novel hybrid welding process called plasma-TIG coupled arc welding was proposed to improve the efficiency and quality of welding by utilizing the full advantage of plasma and TIG welding processes. The two arcs of plasma and TIG were pulled into each other into one coupled arc under the effect of Lorentz force and plasma flow force during welding experiments. The arc behavior of coupled arc was studied by means of it’s arc profile, arc pressure and arc force conditions. The coupled arc pressure distribution measurements were performed. The effects of welding conditions on coupled arc pressure were evaluated and the maximum coupled arc pressure was improved compared with single-plasma arc and single-TIG arc. It was found that the maximum arc pressure was mainly determined by plasma arc current and plasma gas flow. According to the results, the proposed coupled arc welding process have both advantages of plasma arc and TIG method, and it has a broad application prospect.

Investigation of Microstructure and Hardness Properties of Hardfacing Surface on SCM 440 Alloy Steel by Using Metal Active Gas and Flux Cored Arc Welding Processes

2017 ◽  
Vol 728 ◽  
pp. 31-35 ◽  
Author(s):  
Siva Sitthipong ◽  
Prawit Towatana ◽  
Amnuay Sitticharoenchai
Keyword(s):  
Alloy Steel ◽  
Arc Welding ◽  
Welding Process ◽  
High Strength ◽  
Side Plate ◽  
Weld Metals ◽  
Flux Cored Arc Welding ◽  
The Difference ◽  
Arc Welding Process ◽  
Welding Processes

This research aimed to investigate the microstructure and hardness properties of hardfacing surface on SCM440 alloy steel by using metal active gas and flux cored arc welding processes. Due to the difficulty of welding the high strength steel, the changes in base metals’ microstructures were found after welding. Preheating the specimens at 350°C and post weld heat treatment the specimens at 550°C were performed for 1 hour, to reduce the residual stresses and avoid the undesired formation of microstructures. The weld metals’ microstructures that were found from both welding processes are acicular ferrite, polygonal ferrite and side plate ferrite. The hardness value of weld metal resulted from flux cored arc welding process is higher than that of the metal active gas welding process. Each welding process produced different quantities of weld metals’ microstructures, causing the difference in hardness values. The data will be used for investigating and improving parameters of shaft repairing, in order to use it more effectively.

scholarly journals Hardfacing of AISI 1020 Steel by Arc Welding in Comparison with TIG Welding Processes

2012 ◽  
Vol 5 (1) ◽  
pp. 119-126 ◽  
Author(s):  
G. R. C. Pradeep ◽  
A. Ramesh ◽  
B. Durga Prasad
Keyword(s):  
Arc Welding ◽  
Welding Process ◽  
Tig Welding ◽  
Inert Gas ◽  
Sliding Velocity ◽  
Tungsten Inert Gas Welding ◽  
Wear Properties ◽  
Machine Parts ◽  
Arc Welding Process ◽  
Welding Processes

Hardfacing techniques are used for enhancing the life of various machine parts by rebuilding the worn out or eroded or corroded areas in them. In this paper, an attempt has been made to determine the better welding process to hardface AISI 1020 steel based on study of wear and other factors. Two types of welding processes - Arc welding and tungsten inert gas welding (TIG) have been compared. The study revealed that the specimens prepared using TIG welding process yielded better wear properties compared to the specimen prepared using Arc welding process till 1.256 m/s sliding velocity. Also it was observed that the Arc welding process yielded better wear properties for sliding velocities above 1.571 m/s. An attempt was made to study the reasons for getting the said results.© 2013 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v5i1.11899        J. Sci. Res. 5 (1), 119-126 (2013) 

Investigating the Influence of the Power Supply Type upon the Weld Joints Properties and Health Characteristics of the Manual Arc Welding

2011 ◽  
Vol 704-705 ◽  
pp. 608-611 ◽  
Author(s):  
D.P. Ilyaschenko ◽  
D.A. Chinakhov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Power Supply ◽  
Arc Welding ◽  
Welding Process ◽  
Weld Joints ◽  
Manual Arc Welding ◽  
Arc Welding Process ◽  
New Generation ◽  
The Given

The given work considers the influence of the power supply type (diode rectifier ВД-306 and upon new generation inverter Nebula-315) upon the chemical composition, microstructure, mechanical properties of the weld joints and health characteristics of the manual arc welding process.

scholarly journals Arc Welding Process Selection through a Quality and Costs

2019 ◽  
Vol 9 (03) ◽  
Author(s):  
Ashish Thakur1 ◽  
Hagos Gebrelibanos ◽  
Tadesse Gabrey
Keyword(s):  
Arc Welding ◽  
Welding Process ◽  
Labor Cost ◽  
Process Selection ◽  
Financial Loss ◽  
Operational Costs ◽  
Metal Arc Welding ◽  
Quality Costs ◽  
Arc Welding Process ◽  
Welding Processes

This paper presents a methodology to compare three welding processes, namely SAW (submerged arc welding), SMAW (shield metal arc welding) and GMAW (gas metal arc welding) and to select the best one for a given application. Study is the selection of arc welding process for improving quality and welding cost case in MIE and proposes a method for determining the welding process by comparing time, quality and cost, against one over the other of the three types of Arc welding. The welds were carried out in MIE training center. The selection was based on double criteria: operational costs and non-quality costs. The former is related to the normal costs evaluated in such kind of decision, like consumable cost, labor cost, etc. The is the financial loss suffered by the client every time response variable drifts away from its target value or presents variability. The results indicated that the non-quality and operational costs for the SAW process are slightly lower in comparison to the GMAW and SMAW. SAW is selective among them for quality wise. Therefore, it is the best process for the given application. However; cost incurs little high for GMAW.

Investigating the Influence of the Power Supply Type upon the Properties of the Weld Joints under Manual Arc Welding

2014 ◽  
Vol 1040 ◽  
pp. 837-844 ◽  
Author(s):  
D.P. Il’yaschenko ◽  
Dmitry A. Chinakhov ◽  
Y.M. Gotovschik
Keyword(s):  
Power Supply ◽  
Arc Welding ◽  
Impact Resistance ◽  
Welding Process ◽  
Negative Temperature ◽  
Weld Joints ◽  
Manual Arc Welding ◽  
Arc Welding Process ◽  
New Generation ◽  
The Given

The given work considers the influence of the power supply type (diode rectifier DR-306 and inverter Nebula-315) upon the chemical composition, microstructure, mechanical properties of weld joints and upon health characteristics of the manual arc welding process.It has been ascertained that the power supply type has a significant influence upon the weld joints properties and health characteristics of the manual arc welding process. Using a new generation inverter power supply allows less heat input into the weld bead, thus, decreasing silicium and manganese burning, improving impact resistance of weld joints under low (negative) temperature and reduces the risk of respiratory diseases for the workers.

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