The effect of welding speed on microstructures of cold metal transfer deposited AZ31 magnesium alloy clad

The joining of magnesium alloy to galvanized steel was realized by cold metal transfer method with AZ31 magnesium alloy welding wire. Weld appearance, microstructure and tensile properties of Mg–steel joints under various welding parameters were investigated with different welding heat inputs. The results showed that magnesium alloy-steel brazed joints had good weld appearance. When the welding heat input was 141 J/mm, Zn elements were enriched in the Zn-rich zone (ZRZ), and the interface layer was composed of a large portion of Mg–Zn phases and minor Mg–Al phases. With the increase of welding heat input, Zn elements in the ZRZ gradually decreased, Fe/Al phase appeared in the interface layer, and the strength of welding joint increased. When the welding heat input was 159 J/mm, the tensile strength of welding joint reached the maximum value of 198 MPa. However, when the welding input was increased to 181 J/mm, Zn element in the ZRZ was burnt and volatilized seriously, resulting in poor wetting and spreading properties of liquid phase at the interface zone of the steel.

Download Full-text

Effect of welding speed on microstructure and mechanical properties of titanium alloy/stainless steel lap joints during cold metal transfer method

Metallurgical Research & Technology ◽

10.1051/metal/2020052 ◽

2020 ◽

Vol 117 (5) ◽

pp. 506

Author(s):

Gang Li ◽

Shengyu Xu ◽

Xiaofeng Lu ◽

Xiaolei Zhu ◽

Yupeng Guo ◽

...

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Fusion Zone ◽

Welding Speed ◽

Joint Strength ◽

Metal Transfer ◽

Lap Joints ◽

Cold Metal Transfer ◽

Microstructure And Mechanical Properties ◽

Cold Metal

Cold metal transfer (CMT) technique is developed for lap joining of titanium (Ti) alloy to stainless steel (SS) with CuSi3 filler wire. The effect of welding speed on the microstructure and mechanical properties of Ti/SS lap joints is investigated. The results indicate that the wetting angle of the lap joints gradually increases and the weld width decreases with increasing the welding speed. It is found that many coarse phases in the fusion zone are rich in Ti, Fe and Si etc, inferring as Fe–Si–Ti ternary phase and/or Fe2Ti phase at low welding speed. Many fine spherical particles in the fusion zone are considered as iron-rich particles at high welding speed. The transition layer are exhibited at the Ti–Cu interface. With increasing the heat input, the intermetallic layer becomes thicker. A variety of brittle intermetallic compounds (IMCs) are identified in the lap joints. The shear strength of the joints increases with increasing the welding speed. Two fracture modes occur in the lap joints at low welding speed. Thicker reaction layer causes brittle fracture and poor joint strength. The Fe–Ti–Si and Fe2Ti phase within the fusion zone are detrimental to the joint strength. The fracture surface of the joints is dominated by smooth surface and tear pattern at high welding speed. The fracture mode of the joints is merely along the Ti–Cu interface.

Download Full-text

Cold metal transfer welding–brazing of pure titanium TA2 to magnesium alloy AZ31B

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2014.03.051 ◽

2014 ◽

Vol 605 ◽

pp. 12-20 ◽

Cited By ~ 46

Author(s):

R. Cao ◽

T. Wang ◽

C. Wang ◽

Z. Feng ◽

Q. Lin ◽

...

Keyword(s):

Magnesium Alloy ◽

Pure Titanium ◽

Metal Transfer ◽

Cold Metal Transfer ◽

Magnesium Alloy Az31b ◽

Cold Metal Transfer Welding ◽

Cold Metal

Download Full-text

Effects of zinc coating on magnesium alloy–steel joints produced by cold metal transfer method

Materials Science and Technology ◽

10.1080/02670836.2016.1148107 ◽

2016 ◽

Vol 32 (18) ◽

pp. 1805-1817 ◽

Cited By ~ 11

Author(s):

R. Cao ◽

H. X. Zhu ◽

Q. Wang ◽

C. Dong ◽

Q. Lin ◽

...

Keyword(s):

Magnesium Alloy ◽

Alloy Steel ◽

Zinc Coating ◽

Metal Transfer ◽

Cold Metal Transfer ◽

Transfer Method ◽

Cold Metal ◽

Steel Joints

Download Full-text

Welding Investigation on GMAW−Cold Metal Transfer of AISI 201LN for Superior Weld Quality

International Journal of Manufacturing Materials and Mechanical Engineering ◽

10.4018/ijmmme.2020100101 ◽

2020 ◽

Vol 10 (4) ◽

pp. 1-12

Author(s):

Vivek Singh ◽

M. Chandrasekaran ◽

Sutanu Samanta ◽

Kayaroganam Palanikumar

Keyword(s):

Welding Speed ◽

Arc Welding ◽

Gas Metal Arc Welding ◽

Metal Transfer ◽

Weld Quality ◽

Cold Metal Transfer ◽

Gas Tungsten Arc ◽

Metal Arc Welding ◽

Electron Microscope Analysis ◽

Cold Metal

Austenitic stainless steel of AISI 201LN grade has found applications in liquefied natural gas tanks and cryogenic components. They are fabricated using gas tungsten arc welding (GTAW), but weld speed is low due to manual operation. This work aims welding investigation on AISI 201LN Gr. steel with a new hybrid welding approach (i.e., gas metal arc welding [GMAW] combined cold metal transfer [CMT]) for obtaining superior weld quality. Weld experiments were carried out at different welding speed, for example, 300, 400, 600, and 900 mm/min, to study weld quality and its mechanical properties. The microstructural examination of test coupons at higher welding speed shows finer structure in heat-affected zone as well as on weld metal. It was observed that the weld coupon having low heat input (at high weld speed) has maximum tensile strength. Scanning electron microscope analysis shows finer dimples at higher welding speed confirming ductile mode of fracture.

Download Full-text