2020 №06 (03) DOI of Article
2020 №06 (05)

The Paton Welding Journal 2020 #06
TPWJ, 2020, #6, 20-26 pages
Influence of low-temperature tempering on structure and properties of welded joints of high-strength steel 30Kh2N2MF

O.A. Gaivoronskyi, V.D. Poznyakov, O.M. Berdnikova, T.O. Alekseenko and O.S. Shyshkevych
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 results of investigations of influence of low-temperature tempering on structural changes, physical and mechanical properties of HAZ metal and crack resistance of welded joints of high-strength medium-carbon alloy steel 30Kh2N2MF are given. It is shown that the use of a low-temperature tempering is absolutely necessary during welding of products by low-alloy materials, which significantly increases the crack resistance of welded joints. During welding of joints by high-alloy materials in the hardened HAZ metal a relatively more ductile and less stressed structure is formed, in which the maximum level of stresses is lower than that which can be achieved after thermal tempering of a welded joint with a low-alloy weld. Therefore, the level of crack resistance of welded joints is sufficiently high in any case and in this situation there is no need to use low-temperature tempering. This is an unnecessary technological operation that does not significantly affect the reliability during operation of products, but only makes their cost higher. 13 Ref., 4 Tables, 6 Figures.
Keywords: high-strength steel, welded joints, low-temperature tempering, structure, properties, crack resistance

Received 12.05.2020


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