JPH10249581A - Flux for welding, and coated electrode and flux-cared welding wire using the flux - Google Patents

Abstract

PROBLEM TO BE SOLVED: To give sufficient welding strength with promoting fusion at the welding boundary between a base material and a deposit metal and to eliminate preheating/postheating before/after welding by incorporating ferous oxalic anhidride in the flux for welding. SOLUTION: An additive consisting of ferous oxalic anhidride is obtained by heating ferous oxalic dehydrate in an agitation type non-oxidation furnace. A coating film consisting of the flux added with his additive is coated on a core wire, a coated welding electrode for casting is produced. Or, a food fat 3 part, an oyster shell powder 12 part, a manganese acetate quadrihydrate 2 part are added to ferous oxalic dihydrate 1000 part, an additive consisting of an compound containing ferous oxalic anhidride by heating this in an agitation type non-oxidation furnace. A covered electrode for general use is produced by using the flux added with the additive. By this method, a calcium component and a manganese component are contributed to improve performance of a deposit metal, higher welding strength is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to welding for enabling welding of mild steel to steel materials and the like, as well as welding between cast iron and cast iron, welding between dissimilar metals, hardfacing hardening of abrasion resistance and the like. The present invention relates to a flux, a coated welding rod and a cored welding wire using the flux.

[0002]

2. Description of the Related Art Welding flux is used for stabilizing an arc,
Functions such as forming slag, supplying alloy elements to the deposited metal, deoxidizing and scouring the oxide on the base metal and deposited metal, and improving welding workability and the performance of the deposited metal. And is used in the form of, for example, a coating agent for a coated welding rod or a flux cored agent for a cored welding wire.

[0003] However, the conventional welding flux cannot sufficiently cope with welding of various iron and steel materials, particularly between cast iron and cast iron, between different metals, and hardfacing welding on cast iron and carbon steel. In addition, there has been a problem that the fusion of the base metal and the weld metal at the weld boundary is generally insufficient, and a sufficient weld strength cannot be obtained.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention not only to weld ordinary mild steel in various steel materials and the like, but also to weld between cast iron and cast iron, between different metals, and In hardfacing welding of cast iron and carbon steel, etc., a welding flux that promotes fusion of the base metal and the weld metal at the weld boundary to provide sufficient welding strength, a coated welding rod and a cored welding wire using the same Is to provide.

[0005]

A flux for welding according to the present invention is characterized by containing anhydrous ferrous oxalate, thereby forming a slag, especially as a flux for welding, and a method for forming a flux on a base material and a deposited metal. The functions such as the deoxidation scouring of the oxides are remarkably promoted. The appropriate range of the amount of the ferrous oxalate to be added depends on the purpose of welding, the material of the base material and the filler material, the welding method, the flux composition, other welding conditions, the use form of the welding flux, the economical efficiency, and the like. Can vary,
Generally, it can be used well in the range of 0.1 to 15% by weight, particularly 0.5 to 5% by weight.

The above-mentioned ferrous oxalate is usually obtained by heating and dehydrating ferrous oxalate hydrate in a non-oxidized state. The flux may be contained as an anhydrous ferrous oxalate composition obtained by adding an oil / fat component, a calcium component, and manganese acetate and heating this under an unoxidized state. In the case of the above example, the calcium component introduced into the flux at the time of dehydration promotes the densification of the deposited metal, and the manganese component introduced into the flux also contributes to the improvement of the performance of the deposited metal.

[0007] The welding flux containing anhydrous ferrous oxalate is used as the coating agent of a coated welding rod obtained by applying a coating agent to the surface of a metal core wire, or the flux core agent is incorporated inside a metal wire. It can be used as the flux core agent of the cored welding wire thus obtained.

As the basic composition of the welding flux other than the ferrous oxalate anhydride component, a conventionally known composition can be appropriately adopted, and the above-mentioned various functions required as the flux, the coating agent and the flux core are used. In response to the application of physical properties such as coating properties and filling properties as agents and the like, for example, ilmenite, calcium carbonate, iron powder, wollastonite, ferromanganese,
Kali feldspar, manganese dioxide, sodium silicate powder, dolomite, fluorite, rutile sand, mica, etc. are appropriately mixed in consideration of the type of the base material to be welded. Curing and anti-wear components such as ferroboron, tungsten carbide, ferrotungsten, carbon, silicon carbide and the like are appropriately compounded together with soda powder, dolomite and the like.

On the other hand, the filler metal forming the metal core wire of the coated welding rod or the metal wire portion of the cored welding wire preferably has a composition equal to or relatively close to the metal composition of the base metal to be welded. Are appropriately adopted.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. The percentages and parts used in this section are based on weight.

[Production Example 1] Ferrous oxalate dihydrate was heated to 130 to 170 ° C. in a stirring type non-oxidizing furnace to obtain an additive (A-1) comprising anhydrous ferrous oxalate. .

[Production Example 2] Ferrous oxalate dihydrate 10
To 00 parts, 3 parts of edible oil and fat, 12 parts of oyster powder and 2 parts of manganese acetate tetrahydrate were added, and the mixture was heated to 130 to 170 ° C. in a stirring-type non-oxidizing furnace to obtain anhydrous ferrous oxalate. An additive (A-1 ′) composed of a composition containing the compound was obtained.

[Example 1] A known core wire (carbon 0.031
%, Silicon 0.11%, manganese 0.48%, phosphorus 0.0
1%, sulfur 0.014%, iron 99% or more) was coated with a coating agent comprising a welding flux having the following composition in the usual manner, and 3.2 mmφ × 350 mm according to the present invention was applied.
Was produced. Ilmenite 25 parts Calcium carbonate 3 Iron powder 10 Wollastonite 9 Ferromanganese 15 Kali feldspar 12 Manganese dioxide 2 Sodium silicate powder 7 Dolomite 4 Fluorite 4 Rutile sand 5 Mica 5 Additive (A-1) 2.6

Example 2 In Example 1, the additive (A
-1) A coated welding rod for a casting according to the present invention using a welding flux having the same composition as in Example 1 except that 2.6 parts of the additive (A-1 ') was used instead of 2.6 parts. (B-1 ′)
Was manufactured.

Example 3 A coating agent comprising a welding flux having the following composition was formed on the surface of a known core wire similar to that of Example 1, and a 3.2 mmφ × 350 mm according to the present invention was formed.
Of the general-purpose coated welding rod (B-2). Ilmenite 14.5 parts Calcium carbonate 2.5 Iron powder 8 Wollastonite 10 Ferromanganese 15 Kali feldspar 11 Manganese dioxide 2 Sodium silicate powder 4 Dolomite 3.8 Fluorite 2.1 Rutile sand 15 Mica 5 Ferrous oxalate anhydrous (A-1) 3.3

Example 4 In Example 3, the additive (A
-1) A general-purpose coated welding rod according to the present invention (using a welding flux having the same composition as in Example 3 except that 3.3 parts of the additive (A-1 ′) was used instead of 3.3 parts). B-2 ′).

Example 5 A coating material comprising a welding flux having the following composition was formed on the surface of a known core wire similar to that of Example 1, and a 3.2 mmφ × 350 mm according to the present invention was formed.
(B-3) was manufactured. Sodium silicate powder 6 parts Dolomite 17 Ferroboron 7.5 Tungsten carbide 5 Ferrotungsten 50 Carbon 3 Silicon carbide 5.5 Ferrous oxalate anhydride (A-1) 3

Example 6 In Example 5, the additive (A
-1) The wear-resistant coated welding rod (B-) according to the present invention was prepared using a welding flux having the same composition as in Example 5 except that 3 parts of the additive (A-1 ') was used instead of 3 parts. 3 ′) was prepared.

Comparative Example 1 In Example 1, the additive (A
-1) 3.2 mmφ according to the comparative example using a welding flux having the same composition as in Example 1 except that 2.6 parts was excluded.
A coated welding rod (C-1) of × 350 mm for casting was produced.

Comparative Example 2 In Example 3, the additive (A
-1) 3.2 mmφ × 3 according to the comparative example using a welding flux having the same composition as in Example 3 except that 3 parts were excluded.
A 50 mm general-purpose coated welding rod (C-2) was manufactured.

Comparative Example 3 In Example 5, the additive (A
-1) 3.2 mmφ × 3 according to the comparative example using a welding flux having the same composition as in Example 5 except that 3 parts were excluded.
A 50 mm wear-resistant coated welding rod (C-3) was manufactured.

[Weldability Comparison Test 1] The coated welding rods (B-1) and (B-1 ') for casting according to the present invention and the coated welding rod (C-1) for casting according to the comparative example were each prepared. In the case of the former two, the base material and the weld metal were clearly distinguished in the case of the former two by observing the section of each welding boundary with a micrograph (100 × and 400 ×). In the tensile test, the welded portion showed greater strength than the base metal. In particular, in the case of the coated welding rod (B-1 ′), densification of the structure was observed.

At the time of the above-mentioned welding, each of the preheating and postheating processes before and after the welding, which are usually required, could be omitted.

[Weldability Comparison Test 2] The general-purpose coated welding rods (B-2) and (B-2 ') according to the present invention and the coated coating welding rod (C-2) according to the comparative example were respectively Welding was performed on the SS material by a conventional method, and a section at each welding boundary was observed with a micrograph (100 × and 400 ×). In the former two cases, the base metal and the weld metal at the welding boundary were clearly separated. Fusion was observed, and particularly in the case of the coated welding rod (B-2 '), the fusion was good. In addition, in the case of the coated welding rod for casting (C-2) according to the comparative example, the weld boundary was projected in a relatively clear linear shape, and exhibited poor fusion.

In addition, the above-mentioned general-purpose coated welding rod (B-2) in which the additive (A-1) in the welding flux was increased to 10 parts was trial-produced, and the same test was carried out. Good fusion properties similar to those described above were observed.

[Weldability Comparative Test 3] The general-purpose coated welding rods (B-2) and (B-2 ') according to the present invention and the coated coating welding rod (C-2) according to the comparative example were respectively Welding was performed on high manganese steel in a conventional manner, and sections of each weld boundary were observed with micrographs (100 × and 400 ×). In the former two cases, the base metal and weld metal at the weld boundary were clearly identified. Fusion was recognized.

A test piece was prepared from the above-mentioned general-purpose coated welding rod (B-2 ') in which the additive (A-1') in the welding flux was reduced to 2 parts, and the same test was carried out. As compared with the case, a decrease in fusibility at the weld boundary was observed.

[Weldability Comparison Test 4] The general-purpose coated welding rod (B-2) according to the present invention and the general-purpose coated welding rod (C-2) according to the comparative example were each welded to a 55C material by an ordinary method.
A micrograph (100 × and 400 ×) of a section at each weld boundary was taken.
As a result, in the former case, a clear fusion between the base metal and the weld metal at the weld boundary was recognized.

[Weldability Comparative Test 5] The wear-resistant coated welding rods (B-3) and (B-3 ') according to the present invention and the wear-resistant coated welding rod (C-3) according to the comparative example were prepared. Each was welded to a 55C material by a conventional method, and a section at each weld boundary was observed with a microscope photograph (100 times and 400 times). In the former two cases, the weld metal to the base metal at the weld boundary was found. Is clearly observed, especially the coated welding rod (B-3 ')
In the case of, cementite was fixed and the structure was densified.

Further, in the case of the wear-resistant coated welding rod (C-3) according to the comparative example, the welding boundary portion was projected in a relatively clear line shape, and poor fusion was exhibited.

The wear-resistant coated welding rod (B-3)
The additive (A-1) in the welding flux was
Prototypes with increased parts were tested and tested in the same way.
Nearly the same good fusibility as described above was observed at the weld boundary.

[Weldability comparison test 5] After coating the coated welding rod (B-1 ') for casting according to the present invention on an FC material, the wear-resistant coated welding rod (B-3') according to the present invention. When the hardness (Vickers) of the welded portion was measured, the lower embossed portion was 541, but the penetration portion (welded boundary portion) was 71%.
8, welding part upper part is 802, welding part middle is 746,
All showed high values.

[Weldability Comparative Test 6] The wear-resistant coated welding rod (B-3 ') according to the present invention was subjected to SS at an arc current of 130A.
When the hardness (Vickers) of the welded portion was measured, the welded portion (welded boundary portion) was 900, and the upper portion of the welded portion was 9
27, the middle of the weld zone was 920, and all showed high values.

[Weldability Comparative Test 7] The wear-resistant coated welding rod (B-3 ') according to the present invention was subjected to an arc current of 115 A at 55 A.
When welding was performed on the C material and the hardness (Vickers) of the welded portion was measured, the welded portion (weld boundary portion) was 874, the upper portion of the welded portion was 927, and the middle of the welded portion was 907, all showing high values. .

[0035]

As described above, the welding flux according to the present invention and the coated welding rod and the cored welding wire using the same are constructed as described above. -In welding between cast iron and between dissimilar metals, as well as hardfacing welding on cast iron and carbon steel, etc., it is possible to promote fusion of the base metal and the weld metal at the welding boundary to give sufficient welding strength. It is possible to omit the preheating and postheating processes before and after welding in many cases.

[0036] The welding flux is obtained by adding an oil component, a calcium component and manganese acetate to ferrous oxalate hydrate and heating the mixture under non-oxidized condition to obtain an anhydrous ferrous oxalate. When the composition is contained, the calcium component and the manganese component in the composition contribute to the improvement of the performance of the deposited metal, and realize higher welding strength.

Claims (4)

[Claims] 1. A welding flux comprising ferrous oxalate anhydride. 2. An anhydrous ferrous oxalate composition obtained by adding a fat and oil component, a calcium component, and manganese acetate to ferrous oxalate hydrate and heating the mixture under a non-oxidized state. A flux for welding. 3. A coating welding rod obtained by applying a coating agent to the surface of a metal core wire, wherein the welding flux according to claim 1 or 2 is used as the coating agent. 4. A cored welding wire comprising a metal core and a flux core agent incorporated therein, wherein the flux for welding according to claim 1 or 2 is used as the flux core agent.