| Autor: |
Гайворонський, О. А., Позняков, В. Д., Жданов, С. Л., Завдовєєв, А. В., Максименко, А. О., Денисенко, А. М. |
| Zdroj: |
Automatic Welding / Avtomatitcheskaia Svarka; 2023, Issue 10, p3-9, 7p |
| Abstrakt: |
The results of studies on the structure formation in the welds and heat-affected-zone (HAZ) metal of a low-alloy thermally strengthened 13KhGMRB steel in a pulsed-arc welding, changes in mechanical properties and stress intensity factor in brittle fracture and resistance to cold and fatigue cracks formation are given. It was found that compared to stationary arc welding, in a pulsed-arc welding in the structure of welds and HAZ metal of joints, a larger number of hardening structures of bainite and martensite is formed. It was determined that regardless of the welding method, the values of strength (σ0.2 and σt ) and ductility (δ5 and ψ) of metals are approximately at the same level while their ability to resist impact loads, especially at a test temperature -40 °C, in the case of pulsed-arc welding grows. In particular, it was determined that the values of impact toughness of the HAZ metal of welded joints produced using pulsed-arc welding are by 30 % higher compared to arc welding and amount to 108 J/cm² . I.e., the cold resistance of the weld metal is clearly increased. The resistance of weld and HAZ metals to brittle fracture is at a fairly high level (Kq ≥ 84 МPa√m). It was also established that due to an increase of welded joints in the HAZ metal produced using pulsed welding of hardening structures, the temperature of preliminary heating should be increased from 90 to 120 °C to avoid the formation of cold cracks. Instead, such welded joints have a higher resistance to fatigue cracks at cyclic bending load. 18 Ref., 1 Tabl., 7 Fig. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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