CN102233498A - CO2 gas protection flux-cored wire for matching welding of low-alloy steel with strength of 490 MPa - Google Patents

Abstract

The invention relates to a CO2 gas protection flux-cored wire for matching welding of low-alloy steel with the strength of 490 MPa. The CO2 gas protection flux-cored wire is made of a steel belt and flux-cored powder, wherein the flux-cored powder comprises the following components in parts by weight: 4-10 parts of sintering powder, 0.1-0.7 part of Fe3O4, 0-1.0 part of TiO2, 0.1-0.5 part of Al, 0-0.4 part of Ti, 0.1-0.5 part of Si, 2.0-2.5 parts of Mn and 1.0-2.0 parts of Fe. The CO2 gas protection flux-cored wire has the beneficial effects that the mechanical property of the weld metal of the produced flux-cored wire can meet the technical index requirements; the moisture absorption capability of the produced flux-cored wire is greatly improved, so that the pore resistance of the flux-cored wire is enhanced, and i.e., no pore is generated in welding after the unpacked CO2 gas protection flux-cored wire is placed for seven days under the environment with 80% relative moisture.

Description

The supporting welding of intensity 490MPa low-alloy steel CO＜sub〉2＜/sub〉the gas shield flux-cored wire

Technical field

The present invention relates to welding material, relate in particular to the supporting welding CO of a kind of intensity 490MPa low-alloy steel ₂The gas shield flux-cored wire

Background technology

In recent years, in the shipbuilding field, the CO of the full position of wide popularization and application titania-type flux-cored welding wire ₂Automatic and the semi-automatic welding of gas shield.The application of flux-cored wire makes production efficiency improve greatly, and welding deformation greatly reduces, and makes the duration shorten, and production cost reduces.Yet in energy construction particularly in the power plant construction engineering, CO ₂The full position of gas shield titania-type flux-cored welding wire does not still satisfy its specification requirement, mainly shows: 1) mechanical property and power station do not match with the specification requirement of low-alloy steel welding point: as CO ₂The deposited metal intensity of the full position of gas shield titania-type flux-cored welding wire is commonly 3y rank peculiar to vessel, and promptly tensile strength 〉=490MPa, summer of-20 ℃ are than impact absorbing energy 〉=47J.The power station then requires-30 ℃ summer of its weld seam than impact absorbing energy 〉=27J (toughness does not match) with the low-alloy steel (as the 16Mn steel) of tensile strength 〉=490MPa; The power station then requires-20 ℃ summer of its weld seam than impact absorbing energy 〉=47J (intensity does not match) with the low-alloy steel (as 6062 steel) of tensile strength 〉=590MPa; 2) anti-gas porosity is relatively poor etc.

Summary of the invention

The purpose of this invention is to provide the supporting welding CO of a kind of intensity 490MPa low-alloy steel ₂The gas shield flux-cored wire can be at CO ₂Weld under the condition of gas shield, satisfy power plant construction with the deposited metal mechanical property of the low-alloy steel of intensity rank 490MPa welding, have stronger specification requirements such as anti-pore performance.

The objective of the invention is to be achieved through the following technical solutions:

The supporting welding CO of a kind of intensity 490MPa low-alloy steel ₂The gas shield flux-cored wire is made by steel band and medicine core powder, and medicine core powder comprises following compositions in portion by weight: agglomerated powder 4-10, Fe ₃O ₄0.1-0.7, TiO ₂0-1.0, Al 0.1-0.5, Ti 0-0.4, Si 0.1-0.5, Mn 2.0-2.5, Fe 1.0-2.0.

Described agglomerated powder is made by the raw material of following parts by weight: TiO ₂30-80, SiO ₂8-15, MgO 1-7, fluoride 1-7, ZrO ₂1-7, Al ₂O ₃2-10, K ₂O+Na ₂O 0～5.Fully puddle after joining powder by above-mentioned prescription, then through 900 ℃ of high temperature dewater, sintering; Be crushed to behind the certain granules degree compound behind the sintering standby.

Described fluoride is by MgF ₂+ NaF forms, wherein MgF ₂Weight≤40%.

In above-mentioned medicine core powder (containing agglomerated powder) constituent, the effect of each component is as follows: TiO ₂Play slag making and stabilising arc; K ₂O, Na ₂O mainly plays stabilising arc; The main effect of fluoride is the anti-gas porosity that improves welding wire; MgO keeps the certain basicity of slag with fluoride, so that weld metal obtains enough toughness; SiO ₂, Al ₂O ₃, ZrO ₂Deng effect be slag making and the performance effect that improves slag; The effect of Al, Ti, Si is strong deoxidation, with Fe ₃O ₄Deng reaction, bring addition reaction heat to improve the physical property that arc performance and product are improved slag thus; The main effect of Mn is deoxidation and alloying weld metal; The effect of powder sintering is the ability of removing wherein each class moisture and improving its anti-moisture absorption

Beneficial effect of the present invention is: the deposited metal mechanical property of the flux-cored wire of production reaches technical requirement (CO2 gas shield); Anti-moisture absorption ability significantly improves, thereby has strengthened the anti-pore ability of welding wire, show out bag after, the hole holds one's breath in welding (CO2 gas shield) after placing 7 days under the environment of relative humidity 80%.

The specific embodiment

The supporting welding CO of the described intensity 490MPa low-alloy steel of the embodiment of the invention ₂The gas shield flux-cored wire is made by steel band and medicine core powder, and medicine core powder comprises following compositions in portion by weight: agglomerated powder 4-10, Fe ₃O ₄0.1-0.7, TiO ₂0-1.0, Al 0.1-0.5, Ti 0-0.4, Si 0.1-0.5, Mn 2.0-2.5, Fe 1.0-2.0.Described agglomerated powder is made by the raw material of following parts by weight: TiO ₂30-80, SiO ₂8-15, MgO 1-7, fluoride 1-7, ZrO ₂1-7, Al ₂O ₃2-10, K ₂O+Na ₂O 0～5.Described fluoride is by MgF ₂+ NaF forms, wherein MgF ₂Weight≤40%.

According to the composition of flux-cored wire medicine core powder of the present invention, making three batches of trades mark is the NY490 flux-cored wire, and the composition of the three batches of steel bands that welding wire adopted and medicine core powder is as shown in table 1.The three batches of mother metals that welding wire welded and welding process parameter are as shown in table 2.Mechanics Performance Testing and pore detection have been carried out to the deposited metal of gained in the welding back, and test result is as shown in table 3.

Table 1 embodiment NY490 flux-cored wire steel band composition and medicine core composition (weight, %)

Table 2 embodiment NY490 flux-cored wire welding mother metal and welding condition

Table 3 embodiment NY490 flux-cored wire deposited metal mechanical property and pore detect

-30 ℃ of Charpy-V impact powers (Akv, J ,-30 ℃) are the mean value of three samples.

Claims (2)

1. supporting welding CO of intensity 490MPa low-alloy steel ₂The gas shield flux-cored wire is made by steel band and medicine core powder, it is characterized in that: described medicine core powder comprises following compositions in portion by weight: agglomerated powder 4-10, Fe ₃O ₄0.1-0.7, TiO ₂0-1.0, Al 0.1-0.5, Ti 0-0.4, Si 0.1-0.5, Mn 2.0-2.5, Fe 1.0-2.0; Wherein said agglomerated powder is made by the raw material of following parts by weight: TiO ₂30-80, SiO ₂8-15, MgO 1-7, fluoride 1-7, ZrO ₂1-7, Al ₂O ₃2-10, K ₂O+Na ₂O 0～5.

2. the supporting welding CO of intensity 490MPa low-alloy steel according to claim 1 ₂The gas shielded arc welding flux-cored wire is characterized in that: described fluoride comprises MgF ₂Form with NaF, wherein MgF ₂Weight≤40%.