scholarly journals Influence of Stick Electrode Coating’s Moisture Content on the Diffusible Hydrogen in Underwater Wet Shielded Metal Arc Welding

2020 ◽  
Vol 20 (4) ◽  
pp. 27-37
Author(s):  
J. Klett ◽  
T. Hassel
Keyword(s):  
Weld Metal ◽  
Hydrogen Content ◽  
Water Depth ◽  
Arc Welding ◽  
Hydrogen Uptake ◽  
Shielded Metal Arc Welding ◽  
Diffusible Hydrogen ◽  
Relative Contribution ◽  
Metal Arc Welding ◽  
Water Depths

AbstractIn shielded metal arc welding, the major factors influencing hydrogen uptake into the weld metal are (i) the hydrogen content of the base metal, (ii) hydrogen input by the welding consumable, and (iii) the hydrogen introduced by the atmosphere surrounding the arc process. In this study, the relative contribution of these factors is investigated and compared to each other for the case of underwater wet shielded metal arc welding. To assess the influence of the stick electrode’s moisture (capillary introduced water during handling operations) on the diffusible hydrogen in wet welded samples, wet and dry electrodes were welded at four different water depths. The moisture was absorbed through the sharpened electrode tip only, to ensure close to service conditions. The results show that the moist stick electrode coatings lead to 22.6% higher average diffusible hydrogen content in the weld metal (0.5 m water depth an average). However, the effect disappears with increasing water depths (no difference in 60 m water depth).

scholarly journals The Applicability of the Standard DIN EN ISO 3690 for the Analysis of Diffusible Hydrogen Content in Underwater Wet Welding

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3750 ◽  
Author(s):  
Jan Klett ◽  
Thomas Wolf ◽  
Hans Jürgen Maier ◽  
Thomas Hassel
Keyword(s):  
Hydrogen Content ◽  
Arc Welding ◽  
European Standard ◽  
Shielded Metal Arc Welding ◽  
Diffusible Hydrogen ◽  
Underwater Welding ◽  
Arc Voltage ◽  
Underwater Wet Welding ◽  
Metal Arc Welding ◽  
Time Limitations

The European standard ISO 3690 regulates the measurement of diffusible hydrogen in arc-welded metal. It was designed for different welding methods performed in dry atmosphere (20% humidity). Some details of the standard are not applicable for wet underwater welding. The objective of this study was to extend the applicability of DIN EN ISO 3690:2018-12 to underwater wet-shielded metal arc welding (SMAW). Four different aspects regulated within the standard were accounted for: (1) sample dimensions and number of samples taken simultaneously; (2) time limitations defined by the standard regarding the welding and the cleaning process; (3) time, temperature, and method defined for analysis of the diffusible hydrogen content; (4) normalization of the hydrogen concentration measured. Underwater wet welding was performed using an automated, arc voltage-controlled welding machine. The results are discussed in light of standard DIN EN ISO 3690, and recommendations are provided for the analysis of diffusible hydrogen content upon underwater wet welding.

Fracture Mechanics of Conventional and Narrow Groove Pulse Current Gas Metal Arc Welds of HSLA Steel

2012 ◽  
Vol 710 ◽  
pp. 451-456
Author(s):  
Ravi Ranjan Kumar ◽  
P. K. Ghosh
Keyword(s):  
Fracture Toughness ◽  
Weld Metal ◽  
Tensile Properties ◽  
Arc Welding ◽  
Hsla Steel ◽  
Gas Metal Arc Welding ◽  
High Strength ◽  
Compact Tension ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding

Mechanical and fracture properties of 20MnMoNi55 grade high strength low alloy (HSLA) steel welds have been studied. The weld joints were made using Gas Tungsten Arc Welding (GTAW), Shielded Metal Arc Welding (SMAW) and Pulse Gas Metal Arc Welding (P-GMAW) methods on conventional V-groove (V-Groove) and Narrow groove (NG-13). The base metal and weld metal were characterised in terms of their metallurgical, mechanical and fracture toughness properties by following ASTM procedures. The J-Integral fracture test was carried out using compact tension C(T) specimen for base and weld metal. The fracture toughness and tensile properties of welds have been correlated with microstructure. In conventional V-groove welds prepared by P-GMAW shows the improvement in initiation fracture toughness (JIC) as compared to the weld prepared by SMAW. Similar improvements in tensile properties have also been observed. This is attributed to reduction in co-axial dendrite content due to lower heat input during P-GMAW process as compared to SMAW. In the narrow groove P-GMA weld prepared at f value of 0.15 has shown relative improvement of JIC as compared to that of the weld prepared by SMAW process.

scholarly journals The Effect of Cast Iron Preheating on the Microstructure of Welding Results by Using Cin-2 Electrodes

Teknomekanik ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 50-55
Author(s):  
Ahmad Sabirin ◽  
Purwantono Purwantono
Keyword(s):  
Heat Treatment ◽  
Cast Iron ◽  
Weld Metal ◽  
Arc Welding ◽  
Shielded Metal Arc Welding ◽  
Affected Area ◽  
Weld Joints ◽  
Microstructure Observation ◽  
Metal Arc Welding ◽  
The One

Cast iron is commonly found in engineering tools such as machine frames, vise, lathes, planers, pressing tools, V-belt pulleys and others. Cast iron is a metal which is relatively difficult to weld because it contains more than 0.3% carbon. As a matter of fact, a lot of welding workers still experience failure in welding the cast iron, so they require the proper procedures to perform welding on the cast iron like the heat treatment before the welding. This study was aimed at obtaining the effect of preheating variations on the weld joints in which the process of welding the material used the type of open V seam connection. The specimen used was a cast iron with a thickness of 10 mm and the electrode used was the JIS Z 3252 DFCNiFe electrode. The method applied in this research was the microstructure observation testing toward the welding result by using Shielded Metal Arc Welding (SMAW). Based on the results of the study, it can be concluded that by applying the preheating variation treatment on the cast iron welding, there was a change in the microstructure and it was dominated by pearlite-ferrite in the weld metal area. As a result, the rough graphite that looks like roots became smooth after experiencing the preheating treatment because the ferrite was evenly distributed in the heat affected area. To conclude, the most superior specimen for the cast iron preheating among the four specimens was the one with 425oC temperature.

Effects of Welding Positions on Mechanical Properties and Microstructure in Weld Metal of High Strength Steel

2009 ◽  
Vol 83-86 ◽  
pp. 1121-1127 ◽  
Author(s):  
F. Masoumi ◽  
D. Shahriari
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Arc Welding ◽  
High Strength ◽  
Vertical Position ◽  
Shielded Metal Arc Welding ◽  
Tensile Impact ◽  
Metal Arc Welding ◽  
Welding Metal ◽  
Welding Position

In this study the effects of two welding positions included in flat and upward vertical on the mechanical properties and microstructure of high strength weld metal deposited with shielded metal arc welding (SMAW) using an electrode of ASME SFA 5.5-96 E9018B3 type have been investigated. The aim of the present work is to study the effects of these two welding positions for a weld metal alloyed with 1%Mo, 2%Cr, 0.79%Mn, and 0.08% C in the stress relieved condition. For studying mechanical properties Tensile, Impact and hardness experiments have been conducted; meanwhile chemical analysis and microstructure studying have been carried out on specimens. The results show that welding position does not have any significant effect on tensile and hardness of the weld metal but in vertical position welding metal toughness is lower than toughness in flat position in all temperatures. Transition temperature of ductile fracture to brittle fracture is -50 °C for E9018B3 in welding of high strength micro alloyed steels.

Effect of Butt Joint on Mechanical Properties of Welded Low Carbon Steel

2013 ◽  
Vol 845 ◽  
pp. 775-778 ◽  
Author(s):  
Toto Triantoro Budi Wardoyo ◽  
S. Izman ◽  
Denni Kurniawan
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Base Metal ◽  
Arc Welding ◽  
Low Carbon Steel ◽  
Hardness Test ◽  
Butt Joint ◽  
Low Carbon ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding

Effect of variation of the connection (butt joint) in low carbon steel resistance welding (shielded metal arc welding, SMAW) performance is investigated in this paper. Three types of butt joint was varied: square, single V, and double V. The results from tensile test showed that welded specimens are of similar tensile properties with base metal and one another. When hardness test was performed on weld metal, HAZ, and base metal of each specimen,.it was found that weld metal and HAZ were of higher hardness than the base metal. Specimen with square joint exhibits the highest hardness while specimens with single V and double V joints show similar hardness. Microstructure analysis revealed that weld metal of specimen with square joint is of bainite-martensite phases while weld metal of specimens with single V and double V joints are of ferrite-pearlite phases. This difference in microstructure, and hence in hardness, is related to the corresponding heat input during welding.

scholarly journals Effect Of Preheating On The Hardness And Microstructure In Shielded Metal Arc Weldments Of A283 B

2020 ◽  
Vol 5 (2) ◽  
pp. 29-35
Author(s):  
Ali Akbar
Keyword(s):  
Weld Metal ◽  
Arc Welding ◽  
Welding Process ◽  
Current Strength ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Haz Width

The purpose of this study was to determine the effect of heating on the welding process of SMAW (Shielded Metal Arc Welding) in terms of hardness and microstructure of welded metal. Much welding has been done by preheating but below the temperature used below the initial martensitic temperature which reaches 452 ° C, this data is sourced from research by S.Zheng et.al and Y. Huang et.al. For this reason, an experiment was carried out with heat temperatures above a martensitic temperature of 500 ° C. The results show that in the Weld Metal area the pearlite structure appears larger, the effect of current strength on HAZ width is directly proportional, the greater the current strength, the wider HAZ, and hardness are affected by the rough grains of martensite

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