Investigation of the influence of the parameters of the laser welding technological process on the chemical composition, structural-phase state and physicochemical properties of the material of the weld, heat-affected zone, pipe body and product

Using experimental methods of analysis, the morphology, elemental composition and chemical state of hard alloys of the «TiC-TiNi» system in the initial state and after various types of ion-beam treatment have been investigated. It is found that the effect of a continuous ion beam leads to an increase in the microhardness of the investigated alloys by 10–12 %. When samples are irradiated with a pulsed ion beam, as a result of destruction of surface layers, the microhardness value decreases by 20 %, as a result of which this type of modification is not preferable for alloys of the TiC-TiNi system

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The Influence of Welding Mode on the Structural-Phase State of Steel 0.12С-18Cr-10Ni-1Ti-Fe at Welding by Modulated Current

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.303.118 ◽

2020 ◽

Vol 303 ◽

pp. 118-127

Author(s):

A.N. Smirnov ◽

Natalya A. Popova ◽

E.L. Nikonenko ◽

N.V. Ababkov ◽

K.V. Knyazkov ◽

...

Keyword(s):

Martensitic Transformation ◽

Base Metal ◽

Heat Affected Zone ◽

Phase State ◽

Dislocation Substructure ◽

Structural Phase ◽

Droplet Transfer ◽

Structural Phase State ◽

Fine Droplet ◽

Thin Foils

Investigations conducted by transmission electron microscopy on thin foils were aimed at studying the structural-phase state of heat-affected zone of the welding joint performed by modulated current at two welding modes: coarse-droplet and fine-droplet transfer. Welding was conducted on the austenitic steel 0.12С-18Cr-10Ni-1Ti-Fe using the facility UDI-203. Welding modes were: Ii = 175 А (coarse-droplet transfer) and 140 А (fine-droplet transfer). Welding was performed on thin foils sized 200 × 15 × 4 mm3. Investigations were focused on heat-affected zone at the distance of 1 mm from the weld line towards the base metal – the base metal zone and at the distance of 0.5 mm towards the welded metal – the welded metal zone. The studies showed that in the state before welding the steel matrix presents γ-phase (austenite), which has face-centered cubic (fcc) crystal lattice. Morphologically the steel structure is given as grains where defect structure is presented by only network dislocation substructure, and grains where along with the dislocation substructure there are mechanical (or deformation) microtwins in the form of packages of one, two and three systems. It was established that welding of steel 0.12С-18Cr-10Ni-1Ti-Fe by modulated current with coarse-droplet transfer leads to martensitic transformation γ → ε only in the welded metal zone. At fine-droplet transfer welding leads to martensitic transformation γ → ε both in the base metal zone and in the welded metal zone. In the welded metal zone phase transformation γ → ε occurs more intensively. It was revealed that crystal lattice distortion in the whole heat-affected zone at welding by modulated current has only plastic nature, irrespective of the welding mode. Welding by modulated current with fine-droplet transfer leads to lower internal stresses in the whole heat-affected zone.

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Features of chemical composition and structural-phase state decreasing corrosion resistance of parts from 18Cr-10Ni steel

Izvestiya Ferrous Metallurgy ◽

10.17073/0368-0797-2021-3-217-229 ◽

2021 ◽

Vol 64 (3) ◽

pp. 217-229

Author(s):

M. V. Kostina ◽

V. I. Krivorotov ◽

V. S. Kostina ◽

A. E. Kudryashov ◽

S. O. Muradyan

Keyword(s):

Corrosion Resistance ◽

Chemical Composition ◽

Phase State ◽

Structural Phase ◽

Structural Phase State

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Electron-Beam Welding - Structural-Phase State and Microhardnes in the Weld Zone in a Submicrocrystalline Titanium Alloy Grade2

Materials Science Forum ◽

10.4028/www.scientific.net/msf.906.32 ◽

2017 ◽

Vol 906 ◽

pp. 32-37 ◽

Cited By ~ 2

Author(s):

Vasilii A. Klimenov ◽

Anatolii A. Klopotov ◽

Yu.A. Abzaev ◽

K.A. Kurgan ◽

Yu.A. Vlasov

Keyword(s):

Titanium Alloy ◽

Heat Affected Zone ◽

Phase State ◽

Electron Beam Welding ◽

Structural Phase ◽

Weld Zone ◽

X Ray Diffraction ◽

Structural Phase State ◽

X Ray ◽

Microhardness Distribution

The paper presents the results of the X-ray diffraction analysis of structural-phase states in the weld zone of a titanium alloy Grade2 in micro-and submicrocrystalline states. It is established that the structural-phase state in the weld zone and in the heat-affected zone depends on the state of samples of the alloy Grade2 before welding. It is shown that formation process of metastable phases ω-Ti and α′′-Ti occurs in the submicrocrystalline state in the alloy Grade2 in the weld zone and in the heat-affected zone. Investigations of the features of the microhardness distribution in the weld zone in alloys Grade2 in micro-and submicrocrystalline states are carried out. Different character of microhardness distributions in the weld zone in the samples depending on the structural-phase state of welded plates made of alloy Grade2 is determined.

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