Automatic Welding, 2023, №04



2023 №04 (08)

DOI of Article 10.37434/as2023.04.01

2023 №04 (02)

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Avtomaticheskaya Svarka (Automatic Welding), #4, 2023, pp. 3-11

Prevention of cold cracking in armour steel welding

O.A. Gaivoronskyi, V.D. Poznyakov, A.V. Zavdoveyev, A.V. Klapatyuk, A.M. Denisenko

E.O. Paton Electric Welding Institute of the NAS of Ukraine. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

The work presents the results of investigations of cold cracking susceptibility of welded joints on modern high hardness armour steels and gives recommendations on their prevention. Calculations were performed using a calculation method according to EN 1011-2:2001 – the Implant method to determine the delayed fracture resistance of the HAZ metal and rigid technological test in welding multilayer joints. It is found that in arc welding, the joints of high hardness armour steels have a higher cold cracking susceptibility in the HAZ metal. In welding with low-alloyed material of Sv-10GSMT type application of preheating allows avoiding them. The preheating temperature can be calculated by CET and TE indices in keeping with the armour steel composition. In the presence of steel raisers in the welded joints the calculated preheating temperature should be increased by 50 – 70 °C. The welded joints made with high-alloyed material of Sv-08Kh20N9G7T type have higher delayed fracture and cold cracking resistance. In manufacture of light armoured vehicles, it is recommended to select armour steel with carbon content of not more than 0.26 % C. In welding such armour steel by low-alloyed materials sufficiently high cold cracking resistance of welded joints is ensured, even in the presence of stress raisers, due to preheating up to the temperature of 150 °C, as well as in welding without preheating at application of high-alloyed materials. 13 Ref., 4 Tabl., 7 Fig.
Keywords: armour steel, high hardness steel, arc welding, welded joints, HAZ metal, cold cracks


Received: 25.04.2023

References

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