Influence of Weld Heat Input on Weld Joint between B610CF and 16MnR Steel

2010 ◽  
Vol 154-155 ◽  
pp. 421-424
Author(s):  
Tian Hui Zhang ◽  
Hong Cai Fu ◽  
Wen Min Liu ◽  
Yun Chun Cheng ◽  
Ren Ping Xu

The influence of weld heat input on weld joint between B610CF and 16MnR steel using shielded metal arc welding method was investigated by metallographic experiment and mechanical properties experiment. Metallographic experimental results show that in welded metal with the increasing of weld heat input the quantity of bainite is decreased and crystalline grain is larger; but in both B610CF and 16MnR steel heat affected zone, with the increasing of weld heat input there is no distinct difference in microstructure. Mechanical property experimental results show that in weld metal with the increasing of weld heat input the impact toughness decreases, but in both B610CF and 16MnR heat affected zone, there is less difference in impact toughness; and there is no distinct difference in tensile strength and plasticity of weld joint, which is consistent with the metallographic experiment results.

2013 ◽  
Vol 675 ◽  
pp. 270-274
Author(s):  
Yun Chun Chen ◽  
Wen Min Liu ◽  
Hou Sen Yang ◽  
Tian Hui Zhang ◽  
Pei Jun Yan

Weld parameter is an important factor affecting micrographic structure and mechanical properties of weld joints. It was investigated by metallographic experiments and mechanical property experiments for the influence of weld heat input on dissimilar steel weld joint of penstock using B610CF and 16MnR steel in water conservancy and hydropower engineering using shielded metal arc welding method and mixed active gas arc welding method. Metallographic experimental results show that in weld metal with the increase of weld heat input the quantity of bainite decreases and crystalline grain is larger when using the same welding method; but in both B610CF and 16MnR steel heat affected zone, there is no distinct difference in microstructure. Mechanical property experimental results show that in weld metal with the increase of weld heat input the impact toughness decreases when using the same welding method, but in both B610CF and 16MnR heat affected zone, there is less difference in impact toughness; and there is no distinct difference in tensile strength and plasticity of weld joint. So moderate weld heat input is recommended.


2018 ◽  
Vol 937 ◽  
pp. 61-67
Author(s):  
Yu Jie Li ◽  
Jin Wei Lei ◽  
Xuan Wei Lei ◽  
Oleksandr Hress ◽  
Kai Ming Wu

Utilizing submerged arc welding under heat input 50 kJ/cm on 60 mm thick marine engineering structure plate F550, the effect of preheating and post welding heat treatment on the microstructure and impact toughness of coarse-grained heat-affected zone (CGHAZ) has been investigated. The original microstructure of the steel plate is tempered martensite. The yield and tensile strength is 610 and 660 MPa, respectively. The impact absorbed energy at low temperature (-60 °C) at transverse direction reaches about 230~270 J. Welding results show that the preheating at 100 °C did not have obvious influence on the microstructure and toughness; whereas the tempering at 600 °C for 2.5 h after welding could significantly reduce the amount of M-A components in the coarse-grained heat-affected zone and thus improved the low temperature impact toughness.


2018 ◽  
Vol 14 (1) ◽  
pp. 118-127 ◽  
Author(s):  
Emad Kh. Hamd ◽  
Abbas Sh. Alwan ◽  
Ihsan Khalaf Irthiea

In the present study, MIG welding is carried out on low carbon steel type (AISI 1015) by using electrode ER308L of 1.5mm diameter with direct current straight polarity (DCSP). The joint geometry is of a single V-butt joint with one pass welding stroke for different plate thicknesses of 6, 8, and 10 mm. In welding experiments, AISI 1015 plates with dimensions of 200×100mm and edge angle of 60o from both sides are utilized. In this work, three main parameters related to MIG welding process are investigated, which are welding current, welding speed, heat input and plate thickness, and to achieve that three groups of plates are employed each one consists of three plates. The results indicate that increasing the weld heat input (through changing the current and voltage) leads to an increase in widmanstatten ferrite (WF), acicular ferrite (AF) and polygonal ferrite (PF) in FZ region, and a reduction in grain size. It is observed that the micro-hardness of welded AISI 1015 plate increases as the weld heat input decreases. As well as increasing the weld heat input results in an increase in the width of WM and HAZ and a reduction in the impact energy of the weld joint of AISI 1015 at WM region. Also, it is noted the corrosion rate of weld joint increases with increase of Icorr due to increasing in welding current (heat input), corrosion rate increased up to (0.126µm/yr.) with increasing of heat input up to (1.27 KJ/mm).  


10.30544/682 ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 505-517
Author(s):  
Ashok Kumar Srivastava ◽  
Pradip K Patra

With an increasing demand for safer and greener vehicles, mild steel and high strength steel are being replaced by much stronger advanced high strength steels of thinner gauges. However, the welding process of advanced high strength steels is not developed at the same pace. The performance of these welded automotive structural components depends largely on the external and internal quality of weldment. Gas metal arc welding (GMAW) is one of the most common methods used in the automotive industry to join car body parts of dissimilar high strength steels. It is also recognized for its versatility and speed. In this work, after a review of GMAW process and issues in welding of advanced high strength steels, a welding experiment is carried out with varying heat input by using spray and pulse-spray transfer GMAW method with filler wires of three different strength levels. The experiment results, including macro-microstructure, mechanical properties, and microhardness of weld samples, are investigated in detail. Very good weldability of S650MC is demonstrated through the weld joint efficiency > 90%; no crack in bending of weld joints, or fracture of tensile test sample within weld joint or heat affected zone (HAZ), or softening of the HAZ. Pulse spray is superior because of thinner HAZ width and finer microstructure on account of lower heat input. The impact of filler wire strength on weldability is insignificant. However, high strength filler wire (ER100SG) may be chosen as per standard welding practice of matching strength.


2019 ◽  
Vol 269 ◽  
pp. 06003
Author(s):  
Herry Oktadinata ◽  
Winarto Winarto

Various welding methods are widely applied in large fabrication of high strength steel. However, commonly the problem occurs where a coarse grain is formed near fusion zone causing reduce the impact toughness due to the weld joint become brittle. Ductility and toughness in a coarse grain heat affected zone (CGHAZ) is low due to the formation of coarsening grain size. The objective of this research is to investigate the microstructure evolution, impact toughness and fracture appearance at sub-zero temperatures of the high strength steel arc welded. The steel that used in this experiment is a HY-80 steel welded by gas metal arc welding (GMAW) with a mixture of argon and carbon dioxide (90%Ar and 10%CO2) and ER100S solid wire. Microstructure observation and Charpy V-notch (CVN) tests were performed on the weld joint which consist of base metal (BM), heat affected zone (HAZ), and weld metal (WM). The CVN tests on the HY-80 steel plate at various temperatures (20, -20, -60 and -80 °C) show impact toughness decrease when the test temperature decrease. The CVN tests on the HY-80 weld joint at a temperature of 80 °C show the lowest impact toughness was measured at WM (61 J) and followed fusion line-FL (101 J) with brittle fracture appearance.


2010 ◽  
Vol 139-141 ◽  
pp. 352-355 ◽  
Author(s):  
Tian Hui Zhang ◽  
Hong Cai Fu ◽  
Pei Jun Yan ◽  
Fang Wei Jin ◽  
Qiong Wang

Weldability analysis, metallographic experiments and mechanical property experiments were carried out on weld joint between B610CF and 16MnR steel using shielded metal arc welding method and mixed active-gas arc welding method. Weldability analysis shows that the weld joint has some tendency to cold crack, and preheat is needed before welding. Metallographic results show that there are ferrite and bainite in weld metal, and in heat-affected zone of B610CF side there are ferrite and bainite, on which there is much dispersed slight Fe3C, and in heat-affected zone of 16MnR side there are ferrite, pearlite. There is no quenching microstructure resulting in crack in weld joint. From mechanical property results, it can be concluded that the weld joints have excellent impact toughness at low temperature and the tensile strength and plasticity of weld joints is matched to the ones of 16MnR steel. So the welding parameters in this paper are appropriate to get qualified weld joints.


2011 ◽  
Vol 228-229 ◽  
pp. 1196-1200
Author(s):  
Wen Yan Liu ◽  
Ji Bin Liu ◽  
Cong Mao Zhu ◽  
Hui Wang

The experiments were carried out upon the determination of simulated heat-affected zone continuous cooling transformation (SH-CCT) diagrams, the characteristics of microstructure and Vickers hardness of SH-CCT specimens, and impact toughness in simulated coarse grain heat-affected zone (CGHAZ) of ship steels under different heat input based on physical simulation. The SH-CCT diagram reveals that bainite is always obtained in a wide range of cooling rates. When the maximum cooling rate reaches 100 °C/s (t8/5=3 seconds), the maximum fraction of martensite (8%) is obtained and the microstructures mainly consist of lath bainite and the hardness is only 255 HV. This demonstrates that the steel has a low quench-hardening tendency and excellent resistance to cold cracking. There are no obvious hardening and softening phenomena in simulated CGHAZ. Test results of impact toughness under different heat input in simulated CGHAZ show that the impact energies reach over 30 J at -40 °C when t8/5 is less than 20 s, meeting the stipulated requirements of ship steel (≥22 J at -40 °C) but no great allowance. Thus, to meet the requirement of properties during welding, it is proposed to choose t8/5 ranging from 5 to 20 s, correspondently the line energies ranging from 14 to 37 KJ/cm for 30 mm thick plate.


2012 ◽  
Vol 538-541 ◽  
pp. 2003-2008 ◽  
Author(s):  
Zheng Hai Xia ◽  
Xiang Liang Wan ◽  
Xue Li Tao ◽  
Kai Ming Wu

The effect of heat input on toughness of coarse-grained heat-affected zone of an ultra low carbon acicular ferrite steel were investigated when the welding was conducted with high heat input. Microstructural observations, energy dispersive X-ray spectroscopy analyses were conducted using optical microscopy, scanning electron microscopy and transmission electron microscopy, respectively. The microstructures of coarse-grained heat-affected zone consist of predominantly bainitic microstructure and a small proportion of acicular ferrite grains. The bainitic microstructures become coarsened with increasing heat input. The impact toughness of coarse-grained heat-affected zone remained at a higher level when the heat input ranged from 42 to 55 kJ/cm. It became not stable and dropped to a lower level when the heat input increased to 110150 kJ/cm. The enhancement in impact toughness was attributable to the MnS precipitation on the pre-formed Ti oxides as well as the formation of intragranular ferrite. When specimens were welded with higher heat input, the deterioration of impact toughness was caused by the coarsening of austenite grains.


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