Welding method of non-preheating before welding and non-heat-treatment after welding of V-N microalloying Q550D medium plate

A technology without heat treatment after welding and without preheating before welding, which is applied in welding equipment, arc welding equipment, metal processing equipment, etc., can solve the problem of unstable weldability of thick plates such as heat treatment, and promote the nucleation of acicular ferrite , Improve the effect of toughness

Active Publication Date: 2016-12-14
NORTHEASTERN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0008] Aiming at the problems of unstable weldability of V-N microalloyed Q550D medium-thick plates in the prior art and the need for corresponding heat treatment after welding, the present invention provides a V-N micro-alloyed Q550D medium-thick plate without preheating befo...

Method used

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  • Welding method of non-preheating before welding and non-heat-treatment after welding of V-N microalloying Q550D medium plate
  • Welding method of non-preheating before welding and non-heat-treatment after welding of V-N microalloying Q550D medium plate
  • Welding method of non-preheating before welding and non-heat-treatment after welding of V-N microalloying Q550D medium plate

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Effect test

Embodiment 1

[0039] The welding method of the V-N microalloyed Q550D medium and thick plate of this embodiment without preheating before welding and without heat treatment after welding is carried out according to the following steps:

[0040] (1) Make a double V-shaped groove at the joint of the V-N microalloyed Q550D medium and thick plate to be welded, the groove angle is 30°, the blunt edge is 1mm, and the pair gap is 1.5mm; the thickness of the plate to be welded is 20mm, and the yield strength It is 651MPa, the tensile strength is 733MPa, and the elongation is 18.0%;

[0041] (2) Use 400CCR / R sandpaper to grind the groove and the surface of the plate to be welded on both sides to remove scale and rust;

[0042] (3) Fix the medium and thick plates to be welded with bolts, and then carry out Ar+CO 2 Mixed gas shielded tack welding, the welding voltage of tack welding is 20V, the welding current is 180A, the welding speed is 360mm / min, and the input energy is 6.0KJ / cm;

[0043] (4) Af...

Embodiment 2

[0047] The welding method of the V-N microalloyed Q550D medium and thick plate of this embodiment without preheating before welding and without heat treatment after welding is carried out according to the following steps:

[0048] (1) Make a double V-shaped groove at the joint of the V-N microalloyed Q550D medium and thick plate to be welded, the groove angle is 35°, the blunt edge is 2mm, and the pair gap is 2mm; the thickness of the plate to be welded is 20mm, and the yield strength is 651MPa, tensile strength 733MPa, elongation 18.0%;

[0049] (2) Use 400CCR / R sandpaper to grind the groove and the surface of the plate to be welded on both sides to remove scale and rust;

[0050] (3) Fix the medium and thick plates to be welded with bolts, and then carry out Ar+CO 2 Mixed gas shielded tack welding, the welding voltage of tack welding is 23.5V, the welding current is 196A, the welding speed is 390mm / min, and the input energy is 7.1KJ / cm;

[0051] (4) After the tack welding ...

Embodiment 3

[0055] The welding method of the V-N microalloyed Q550D medium and thick plate of this embodiment without preheating before welding and without heat treatment after welding is carried out according to the following steps:

[0056] (1) Make a double V-shaped groove at the joint of the V-N microalloyed Q550D medium and thick plate to be welded, the groove angle is 40°, the blunt edge is 2mm, and the pairing gap is 2mm; the thickness of the plate to be welded is 30mm, and the yield strength is 625MPa, tensile strength 724MPa, elongation 20.0%;

[0057] (2) Use 400CCR / R sandpaper to grind the groove and the surface of the plate to be welded on both sides to remove scale and rust;

[0058] (3) Fix the medium and thick plates to be welded with bolts, and then carry out Ar+CO 2 Mixed gas shielded tack welding, the welding voltage of tack welding is 24V, the welding current is 200A, the welding speed is 330mm / min, and the heat input=8.7KJ / cm;

[0059] (4) After the tack welding is c...

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Abstract

The invention belongs to the technical field of welding, and particularly relates to a welding method of non-preheating before welding and non-heat-treatment after welding of a V-N microalloying Q550D medium plate. Through selection of reasonable welding wires and optimization of welding parameters, the welding technology of non-preheating before welding and non-heat-treatment after welding is developed; a VN precipitated phase in austenite of V-N microalloying steel is used for promoting the acicular ferrite nucleation action, the toughness performance of a welding heat affected zone is improved, and the welding technology has the important significance in applying and popularizing of the V-N steel.

Description

technical field [0001] The invention belongs to the field of welding technology, and in particular relates to a welding method for a V-N microalloyed Q550D medium-thick plate without preheating before welding and without heat treatment after welding. Background technique [0002] Q550D steel is a low-alloy high-strength steel with a yield strength of 550MPa. Its components are mainly medium and thick plates. It is widely used in many fields such as oil and gas pipelines, construction machinery, bridges, ships, and coal mine hydraulic supports. At present, new production processes of Q550D hot-rolled steel plates are constantly emerging, but the related welding process lags behind the rolling process, which limits the practical application of Q550D medium and thick plates to a certain extent. [0003] The process of producing non-quenched and tempered high-strength steel by V-N microalloying combined with controlled rolling and controlled cooling (TMCP) has become increasingl...

Claims

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Application Information

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IPC IPC(8): B23K9/16B23K33/00B23K9/235
CPCB23K9/16B23K9/235B23K33/00
Inventor 齐祥羽胡军张彬翁镭高秀华杜林秀
Owner NORTHEASTERN UNIV
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