RU2632505C1 - Powder wire - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: powder wire consists of a steel shell and a charge containing ferromanganese powders, ferrosilicon, ferrochrome, ferromolybdenum, ferrovanadium, iron, nickel, cobalt, ferroboron and carbon fluoride dust filters of aluminium production, with the ratio of the components of the wire, wt %: steel shell 67.0-68.0, ferromanganese 1.6-8.0, ferrosilicon 0.80-2.88, ferrochrome 0.90-9.2, ferromolybdenum 0.05-3.80, ferrovanadium 0.50-5.0, nickel 0.01-2.5, cobalt 0.003-0.19, ferroboron 0.006-0.47, carbon fluoride dust filters of aluminium production 1.30-5.80, iron is the rest.

EFFECT: invention allows to increase the wear resistance and hardness of the weld metal, to prevent the formation of cracks due to the elimination of pore formation and to reduce the hydrogen content in the weld metal, to reduce the cost of the welding process by optimizing the composition of the charge and efficient use of production waste.

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Description

The invention relates to welding consumables and can be used for submerged arc surfacing to restore worn parts and obtain a wear-resistant protective coating on parts of mining equipment operating under abrasive conditions.

A known mixture of flux-cored wire [1] containing ferrosilicon, ferromolybdenum, ferrotitanium, graphite, molybdenum powder, ferrochrome, aluminum-magnesium powder and yttrium in the following ratio, wt.%:

Ferrosilicon 1.5-3.0 Ferromanganese 4.0-9.0 Ferrotitanium 4.0-9.0 Graphite 2.0-6.0 Molybdenum powder 2.0-6.0 Aluminum Magnesium Powder 1.0-2.4 Yttrium 0.5-5.0 Ferrochrome rest

Significant disadvantages of this cored wire are:

- low resistance of the weld metal due to the formation of a large number of non-metallic oxide inclusions of aluminosilicates associated with the use of aluminum-magnesium powder;

- the high cost of cored wire in connection with the use of expensive materials in significant quantities (in particular, yttrium);

- low quality deposited metal associated with pore formation and a high hydrogen content due to the absence of fluorine-containing elements.

Also known is the composition of the charge for surfacing [2], containing ferrochrome, ferroboron, ferromanganese, nickel powder and aluminum in the following ratio of components, wt. %:

Ferrochrome 70-74 Ferroboron 2-4 Ferromanganese 6-8 Nickel powder 14-16 Aluminum 2-4

Significant disadvantages of this cored wire are:

- low quality of the deposited metal due to pore formation associated with an increased hydrogen content, which, in turn, is predetermined by the absence of fluorine-containing components in the composition;

- low resistance of weld metal to abrasion associated with the claimed chemical composition;

- the high cost of cored wire due to the use of significant amounts of Nickel and ferrochrome.

Known as a prototype [3] is a flux-cored wire consisting of a steel sheath and a powder mixture containing ferromanganese, ferrosilicon, ferrochrome, ferromolybdenum, ferrovanadium, iron powder, carbon-containing dust from aluminum filters with a ratio of components, mass. %:

Steel sheath 67.0-68.0 Ferromanganese 0.50-1.20 Ferrosilicon 1.0-1.75 Ferrochrome 7.2-9.1 Ferromolybdenum 1.5-2.3 Ferrovanadium 0.6-0.8 Carbon fluoride dust filters aluminum production 0.70-1.20 Iron powder rest

Significant disadvantages of this cored wire are:

- low quality deposited metal due to pore formation associated with a high hydrogen content;

- low toughness and resistance of weld metal to abrasion;

- the high cost of the welding process through the use of expensive materials in significant quantities (tungsten and sodium silicofluoride).

The technical results of the invention are:

- increase the wear resistance and hardness of the weld metal;

- prevention of cracking due to the elimination of pore formation and a decrease in the hydrogen content in the weld metal;

- reducing the cost of the welding process by optimizing the composition of the charge and the efficient use of production waste.

For this purpose, a flux-cored wire is proposed, consisting of a steel sheath and a powder mixture containing ferromanganese, ferrosilicon, ferrochrome, ferromolybdenum, ferrovanadium, carbon-containing dust from aluminum filters, iron powder, in which the powder mixture additionally contains nickel, cobalt and ferroboron in the ratio of components, oil . %:

Steel sheath 67.0-68.0 Ferromanganese 1,60-8,0 Ferrosilicon 0.80-2.88 Ferrochrome 0.90-9.2 Ferromolybdenum 0.05-3.80 Ferrovanadium 0.50-5.00 Nickel 0.01-2.5 Cobalt 0.003-0.19 Ferroboron 0.006-0.47 Carbon fluoride dust filters aluminum production 1.30-5.80 Iron powder rest

The claimed limits are selected empirically based on the quality of the metal obtained during surfacing, the stability of the welding process, preventing the formation of cold cracks and obtaining the required mechanical properties.

Nickel, cobalt and ferroboron are additionally introduced into the composition of the charge based on the following premises.

The introduction of the mixture of Nickel can significantly reduce the actual grain and provide increased hardness of the deposited layer.

The introduction of cobalt into the mixture allows to increase the “adhesion” of the deposited layer and to exclude cracking during heating due to friction on the surface of the deposited layer of transported materials.

The addition of ferroboron within the claimed limits allows to reduce the actual grain and improve the deoxidizing ability of the mixture.

Introduction to the composition of the flux-cored wire charge of an increased amount of carbon-fluorinated dust filters of aluminum production allows:

- increase the degree of hydrogen removal due to a complex of fluorine-containing compounds that decompose at welding process temperatures with the release of fluorine, which in turn interacts with hydrogen dissolved in steel to form gaseous compounds of the HF type;

- increase the concentration of carbon in the deposited layer due to the intensive carburization during interaction CF _x (1≥х>0);

- reduce the likelihood of the formation of pores and cold cracks in the weld metal by reducing the concentration of hydrogen in the weld metal.

For the manufacture of a mixture of flux-cored wire used carbon-fluorine-containing dust filters of aluminum production with the following chemical composition, wt. %: Al ₂ O ₃ = 19-48; F = 17-28; Na ₂ O = 2.8-12; K ₂ O = 0.36-6.0; CaO = 0.6-1.8; SiO ₂ = 0.5-2.7; Fe ₂ O ₃ = 1.7-3.6; With _total = 22-30; MnO = 0.05-l, 2; MgO = 0.06-0.87; S = 0.09-0.34; Ρ = 0.09-0.15.

The change in the content of carbon-containing dust of aluminum filters in the composition of the inventive charge was carried out taking into account the production of high-quality deposited metal (good formation of a deposited bead, dense weld metal without cracks, pores and non-metallic inclusions), while taking into account the content of other components that affect hardness, impact strength and wear resistance obtained during surfacing of metal.

In the manufacture of cored wire used: iron powder grade ПЖВ1 according to GOST 9849-86, nickel powder PNK-1L5 according to GOST 9722-97, cobalt powder PK-1U according to GOST 9721 -79, carbon ferromanganese powder FMn 78 (A) according to GOST 4755- 91, FS 75 grade ferrosilicon powder in accordance with GOST1415-93, ФХ900А grade high carbon ferrochrome powder in accordance with GOST 4757-91, ФМо60 grade ferromolybdenum powder in accordance with GOST 4759-91, ФВ50У0,6 grade ferrovanadium powder in accordance with GOST 27130-94 and ФБ20 grade ferroboron powder in GOST 14848-69.

The powders were mixed in a mixer to obtain a homogeneous mass, and then calcined to remove moisture at a temperature of (250-350) ° C. Next, carbon-fluorinated dust of aluminum filters was introduced. The manufacture of cored wire was carried out on the machine. The diameter of the finished wire after drawing operations was 3.6 mm with a fill factor of 0.32. The flux-cored wire with the proposed charge was used for surfacing of steel plates from steel 3sp. Surfacing was performed under the AN-20 flux using an ASAW-1250 welding tractor.

The presence of cracks in the surfacing process was visually evaluated, quality control was carried out by the ultrasonic method, as well as using metallographic sections cut from the deposited rollers. The hydrogen content in the deposited metal was determined on a gas analyzer company "LECO" TC-600 (USA). Hydrogen content was varied in the range 0.2-0.6 cm ^3/100 g of weld metal with an acceptable hydrogen content in the high alloy weld metal to 2 cm ³ / 100g metal. The hardness of the deposited metal was monitored immediately after surfacing. The hardness of the deposited metal after surfacing was 44-49 HRC. Defects (cracks, pores and non-metallic inclusions) during surfacing with flux-cored wire with a charge of the claimed composition containing dust from aluminum electrostatic precipitators were not detected. After the deposition of the rollers on the plates, the samples were cut and abrasion tested on the 2070 SMT-1 machine.

Table 1 shows 5 options for the composition of the mixture of flux-cored wire with foreign and claimed limits.

The effect of changes in chemical composition on the technological properties and mechanical characteristics of the deposited metal are shown in table 2. Using the inventive flux-cored wire in comparison with the prototype allows you to:

1. To improve the quality of the deposited metal by reducing its contamination with non-metallic inclusions, reduce the likelihood of pore formation and prevent the formation of cold cracks.

2. Reduce the hydrogen content by the introduction of fluorine-containing components and create an extra gas protection in the average of 0.3-0.6 cm ³ / 100g metal.

3. Increase the hardness of the weld metal to 44-49 HRC.

4. To reduce the cost of manufacturing flux-cored wire by reducing the content of alloying components and the use of aluminum waste.

Information sources

1. A.S. USSR No. 563252, M. Cl ² V23K 35/368.

2. A.S. USSR No. 539624, M. Cl ² V23K 35/368.

3. RF patent No. 2518035, cl. B23K 35/368.

Claims (2)

A flux-cored wire consisting of a steel sheath and a mixture containing powders of ferromanganese, ferrosilicon, ferrochrome, ferromolybdenum, ferrovanadium, iron and carbon-containing dust from aluminum filters, characterized in that it additionally contains nickel, cobalt and ferroboron powders in the following ratio of wire components, wt . %: steel sheath 67.0-68.0 ferromanganese 1.6-8.0 ferrosilicon 0.80-2.88 ferrochrome 0.90-9.2 ferromolybdenum 0.05-3.80 ferrovanadium 0.50-5.00 nickel 0.01-2.5 cobalt 0.003-0.19 ferroboron 0.006-0.47 carbon fluoride dust filters aluminum production 1.30-5.80 iron rest