Properties of welded joints in high-strength pipe steels produced by welding with a continuous CO2laser

AbstractNowadays, ultra-high hard armor (UHA) steels are employed in armor tracked vehicle (ATV) construction because of their high hardness, high strength to weight ratio, and excellent toughness. UHA steels are usually welded using austenitic stainless steel (ASS) welding consumables, to avoid hydrogen-induced cracking (HIC). The use of ASS consumables to weld the above steel was the only available remedy because of higher solubility of hydrogen in the austenitic phase. In this investigation, an attempt was made to investigate the effect of ASS consumables (with different Creq/Nieq ratio) on solidification mode, impact toughness and microstructural characteristics of shielded metal arc (SMA) welded UHA steel joints. The welded joints were characterised based on impact toughness properties, hardness, and microstructural features. As the ferrite number increases with an increase in Creq/Nieq ratio result in different solidification mode (A, FA, F). It is also found that ferrite number of weld metal has appreciable influence on impact toughness and has inversely proportional relationship with impact toughness of the welded joints.

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Residual stress effects on fatigue life prediction using hardness measurements for butt-welded joints made of high strength steels

International Journal of Fatigue ◽

10.1016/j.ijfatigue.2021.106175 ◽

2021 ◽

Vol 147 ◽

pp. 106175

Author(s):

Haohui Xin ◽

José A.F.O. Correia ◽

Milan Veljkovic ◽

Filippo Berto ◽

Lance Manuel

Keyword(s):

Residual Stress ◽

Fatigue Life ◽

Welded Joints ◽

Life Prediction ◽

High Strength Steels ◽

High Strength ◽

Fatigue Life Prediction ◽

Stress Effects

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Control of Cold Welding Cracks in 30CrMnSi Steel by Welding with Trailing Impacting and Rolling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.295-297.1251 ◽

2011 ◽

Vol 295-297 ◽

pp. 1251-1258 ◽

Cited By ~ 1

Author(s):

Jian Guo Yang ◽

Lu Yong Huang ◽

Hai Bo Pan ◽

Xue Song Liu ◽

Hong Yuan Fang

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Welded Joints ◽

High Strength ◽

Cold Welding ◽

Low Alloy Steel ◽

Residual Welding Stress ◽

Welding Stress ◽

Scanning Electron ◽

Main Factor

As a kind of the high strength low alloy steel (HSLA), 30CrMoSi has been used widely in some industrial fields. However, just like some HSLA, this steel also faces some problems when it is welded, especially such problem as cold cracking in the welded joints. In this paper, the cold welding cracks and microstructure of the joints of 30CrMoSi steel were studied by scanning electron microscopy (SEM) and optical microscopy (OM), and a method called welding with trailing impacting and rolling (WTIR) was utilized to solve the problem mentioned above by decreasing the residual welding stress which is one main factor to lead to cold welding crack in the joint of HSLA. The crack-free joints of 30CrMoSi steel were obtained by using proper parameters.

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