WO1999018174A1

WO1999018174A1 - Ethylene mixture composition for gas pressure welding of steel materials

Info

Publication number: WO1999018174A1
Application number: PCT/JP1998/004410
Authority: WO
Inventors: Yasunobu Yamazaki; Mamoru Takahashi; Kou Yasutomi; Atsushi Matsumoto
Original assignee: Toagosei Co., Ltd.; MATSUMOTO, Kimiko
Priority date: 1997-10-02
Filing date: 1998-09-30
Publication date: 1999-04-15
Also published as: JPH11106769A

Abstract

A combustible gaseous ethylene mixture composition for the gas pressure welding of steel materials, which is less expensive than acetylene gas, has an excellent safety, and comprises 100 parts by weight of ethylene and 0.1 to 30 parts by weight of at least one organic compound selected from among the following compounds (1) to (5): (1) hydrocarbons having 5 to 12 carbon atoms, (2) alcohols having 1 to 12 carbon atoms, (3) ethers having 2 to 12 carbon atoms, (4) ketones having 3 to 12 carbon atoms, and (5) esters having 3 to 12 carbon atoms.

Description

Specification

Ethylene mixture composition for steel gas pressure welding

The present invention relates to a flammable gas used for joining steel materials by a gas pressure welding method, and relates to a highly safe and inexpensive ethylene mixed composition for steel gas pressure welding comprising ethylene and a specific organic compound. Background art

Generally, the method of joining steel materials by the gas pressure welding method is as follows. First, make the joint surface as perpendicular to the axis as possible, finish it smooth and clean by grinder grinding, then abut the end surfaces without intervening any foreign matter on the joint surface, and use a pressure welder (support). Clamp and then pressurize in the axial direction (standard 30 to 50 MPa), and heat the area around the butted part with an oxygen gas / acetylene gas mixed flame using a porous ring burner. As a result, the area near the butted portion is glowed red with time, causing plastic deformation and a slight swelling (initial pressure welding). Since then, there is no concern about internal oxidation, so the burner is oscillated while adjusting to a flame using a mixed gas with a mixed volume ratio of oxygen gas / acetylene gas of about 1: 1 as a fuel. Heat around it. When the specified amount of compression is reached, release the pressure, extinguish the burner and end the pressure welding. In the above method, as the carbon content in the steel material to be joined is larger, or as the gap between the butted surfaces is smaller, a flat fracture surface is less likely to be generated, and the pressure contact property is improved. This flat fractured surface is a smooth, non-crystalline grayish-white or black-gray color that is observed in a fractured surface fractured from the joint in a tensile or bending test of a pressed steel. A broken surface. This is a poor weld that results from poor or inadequate metal diffusion due to the formation of an oxide film on the joint surface when the steel composition, welding conditions or construction are inappropriate.

The so-called reducing flame method or the acetylene injection method has been improved to eliminate the flat fracture surface.These methods use an acetylene gas excess flame for heating the initial pressure welding. Using a reducing flame (using a mixed gas with an oxygen gas / acetylene gas volume ratio of approximately 1: 1.3 as fuel) for the heating during initial pressure welding until the compression swelling occurs, the heating atmosphere is changed to a strong reducing property, The gas pressure welding is improved by preventing or suppressing the oxidation of the joint surface.

However, acetylene is expensive, and the pressure welding cost is high in the reducing flame method or the acetylene injection method. Also, acetylene is filled in a cylinder to prevent its explosion, and dissolved in acetone or dimethylformamide for storage.Therefore, the amount of acetylene is small relative to the volume of the cylinder. Transport costs are high and very large spaces are required to store large amounts of acetylene.

Furthermore, since it is dissolved in acetone or dimethylformamide, the vaporization capacity of acetylene in the cylinder is low, and it is necessary to secure several cylinders in parallel in winter when the temperature is low. Also, there is a risk of acetone or dimethylformamide escaping from the cylinder.

In addition, acetylene is prone to flashbacks and requires strict monitoring during work.If flashbacks occur, burners will be damaged, workers will be burned, and explosions will be triggered. There is a problem.

On the other hand, when welding steel materials, the thermal power is too strong in the case of acetylene gas, There is a problem that the surface of the steel material is excessively burned.

An object of the present invention is to provide a flammable gas for steel gas pressure welding that exhibits excellent performance in steel pressure welding, is highly safe, and is economically excellent, instead of acetylene gas. Disclosure of the invention

The present inventors have conducted intensive studies on a method of performing gas pressure welding of steel using a combustible gas other than acetylene, and as a result, if a mixed composition of ethylene and a specific organic compound is used as a combustible gas, Compared to the case where acetylene gas is used, gas pressure welding of steel material can be performed without excessive burning of the surface of the steel material, and the mixed composition has higher safety and is economically superior to acetylene Thus, the present invention has been completed.

That is, the present invention comprises ethylene and at least one organic compound selected from the following (1) to (5), wherein the organic compound is contained in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of ethylene. It is an ethylene mixed composition for steel material gas pressure welding which is a part by weight.

(1) Hydrocarbons having 5 to 12 carbon atoms

(2) Alcohols having 1 to 12 carbon atoms

(3) Ethers having 2 to 12 carbon atoms

(4) Ketones having 3 to 12 carbon atoms

(5) Esters having 3 to 12 carbon atoms

The mixed composition for gas pressure welding of steel according to the present invention is a mixture of ethylene and an organic compound. As a mixing method, a liquid-liquid state may be mixed under pressure in a pressure vessel such as a cylinder. Alternatively, a cylinder filled only with ethylene and a device for vaporizing an organic compound may be combined and mixed in a gas-gas state. No.

The ethylene used in the present invention is used as an industrial raw material without any particular purification, and can be used as it is, and its purity is preferably at least 99 mol%.

(1) Pentane, n-hexane, 1-hexene, i-hexane, n-heptane, 1-heptene used as the organic compound in the present invention include (1) hydrocarbons having 5 to 12 carbon atoms. , I-heptane, n-octane, 1-octene, i-octane, neooctane, n-nonane, n-decane, i-decane, n-dodecane, cyclopentane, cyclopentene, cyclohexane, cyclohexene, methylcyclo Hexane, ethyl hexane, dimethyl cyclohexane, benzene, toluene, ethyl benzene, xylene, vinyl benzene and a mixture of the above compounds as the main components, and are generally known petroleum fractions such as gasoline, kerosene, and gas oil. (2) Examples of alcohols having 1 to 12 carbon atoms include methanol, ethanol, and n-propano. , I-propanol, n-propanol, 2-butanol, n-pentanol, n-hexanol, cyclopentanol, cyclohexanol, n-decanol and n_dodecanol, and the like. 3) Ethers having 2 to 12 carbon atoms include getyl ether, ethyl methyl ether, getyl ether, i-propyl ether, dihexyl ether, ethyl vinyl ether, tetrahydrofuran, 1,4 —Dioxane and 1,3-dioxane; and (4) ketones having 3 to 12 carbon atoms include acetone, methylethylketone, 2-pentynone, and 3— (5) Examples of esters having 3 to 12 carbon atoms include methyl acetate, ethyl acetate, ethyl ethyl butyrate, and ethyl acetate. Such Purobiru and acetic Isobuchiru and the like, these organic compounds two Or more can be used in combination. Among these organic compounds, hydrocarbons (1), particularly aromatic hydrocarbons, which generate a large amount of soot and smoke, which have the effect of preventing or suppressing oxidation during pressure welding, are preferred.

Preferred specific compounds are preferably toluene, acetone, methanol and oxane in terms of flammability, and toluene is a particularly preferable compound for the above reasons.

The ratio of ethylene to the organic compound is 0.1 to 30 parts by weight, preferably 1 to 15 parts by weight, based on 100 parts by weight of ethylene. When the proportion of the organic compound exceeds 30 parts by weight, the mixture is hardly vaporized, while when the proportion is less than 0.1 part by weight, the effect of the added compound is not exhibited.

Further, in the ethylene mixture composition for steel gas pressure welding, other flammable hydrocarbons may be contained in addition to the ethylene and the organic compound.As other flammable hydrocarbons, for example, LPG (propane, butane and Butene), LNG (mainly composed of methane), ethane, acetylene, methylacetylene, propylene and the like. These are desirably used in a range of 30% by weight or less of the whole mixed composition. .

The ethylene mixture composition for steel gas pressure welding according to the present invention can be used in the same manner as the conventional pressure welding method using acetylene gas. In the steel gas pressure welding, the ethylene mixture composition is mixed with oxygen gas or air. In this case, the volume ratio of the mixed composition to oxygen gas or air is preferably 1: 0.5 to 2.5, and more preferably 1: 1.0 to 2.0. is there. If the volume ratio is less than 1: 0.5, the burner's thermal power is small, and the welding time is unnecessarily long, which is not economical. Conversely, if the volume ratio is greater than 1: 2.5, the burner will be overheated and the steel will melt and fall, causing a fire. If the ratio of oxygen gas is too large, an oxide film will be formed on the joint surface, and the mechanical strength of the welded portion of the steel will decrease. In particular, when heated by a flame with a large oxygen ratio at the time of initial pressure welding, an oxide film is easily formed, which greatly affects the mechanical strength.

Next, an example of a steel gas pressure welding method using the steel gas pressure welding ethylene mixed composition as a combustible gas for fuel will be described below.

As the steel material to be used, general steel processed into a machine or building material can be used without any particular limitation.

First, the joint end face of the steel material is made as perpendicular to the axis as possible, and after smooth and clean finishing by grinder grinding, the end faces are joined to each other without intervening any foreign matter on the joint end face, and a pressure welder (supporter) is used. ) Clamp with. At this time, a manual pressure welding device, a semi-automatic pressure welding device, an automatic pressure welding device, and the like used in the prior art can be used.

Next, the periphery of the butted portion is heated using a burner while applying pressure in the axial direction (standard 30 to 50 MPa).

As described above, the mixing volume ratio of the ethylene mixture composition for steel gas pressure welding and oxygen gas is preferably in the range of 1: 0.5 to 2.5, and this mixing volume ratio is maintained constant during the welding of the steel material gas. However, in order to avoid the formation of an oxide film on the bonding surface, the ratio of oxygen gas (for example, ethylene mixed composition: oxygen gas = 1: 1.0 to 1.4) should be reduced in the initial stage. Then, it is desirable to increase the ratio of oxygen gas.

When the joint surface is heated by the above-described method, the vicinity of the butted portion is heated red, causing plastic deformation and slight swelling. After that, the vicinity of the joint is heated while the burner is oscillating. When the specified amount of compression is reached, release the pressure, extinguish the burner and end the pressure welding. At this time, the temperature of the pressure contact part is The temperature is preferably 1,300 ° C. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples as long as the gist of the present invention is not exceeded.

In the following Examples, gas pressure welding tests were performed on steel materials using flammable gas and oxygen gas of various compositions. In addition, SD345-D25 described in JISG3112 was used as the steel material.

As the evaluation of the pressure welding results, for each test piece obtained by gas pressure welding, the appearance was observed (with or without burning cracks or sagging), and a notch was inserted into the joint to bend and break. The area ratio of the fracture surface was determined, and the specimens separately pressed under the same conditions were subjected to a tensile test in accordance with the method described in JISZ 3120 (Method for inspecting steel-plate gas-welded joints for reinforced concrete). Example 1

Using a composition in which 5.0 parts by weight of toluene was mixed with 100 parts by weight of ethylene, the steel material was subjected to gas pressure welding. Initial pressure welding until the joint is compressed by 5 mm is performed by supplying an amount of 43.5 l / min of oxygen gas to 33.5 l / min of the ethylene mixture composition, and then the joint is compressed by 25 mm Until the above, 30.0 l / min of the ethylene mixed composition was supplied at a rate of 50.0 l / min of oxygen gas. The time required for the joint to compress 5 mm and adhere to each other (adhesion time) was 70 seconds, and the time required to compress to 25 mm and finish heating (sintering time) was 60 seconds, for a total of 130 seconds. Was. The results are shown in Table 1 below.

App. Ι | 2〜 App. 17

A composition in which organic compounds of the types and ratios shown in Table 1 were mixed with ethylene was used. Except for the above, a gas pressure welding test was performed on the steel material in the same manner as in Example 1, and the results are shown in Table 1.

Hito I Ί

The gas pressure welding of the steel material was performed in the same manner as in Example 1 except that only ethylene was used, and the results are shown in Table 1.

table 1

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 1 Ethylene 100 parts by weight 100 parts by weight 100 parts by weight 100 parts by weight 100 parts by weight 100 parts by weight lOOffl part by weight Organic additives Toluene 5 parts by weight 2ffl parts by weight 2 parts by weight

Octane 4ffl part 2ffl part

Methanol lffl part

Acetone 1 part by weight l ffl amount part

= 1 =-Jechläter

g Methyl acid 邬 Gas flow rate ① Mixed gas 33.5 33.5 33.5 33.5 33.5 33.5 33.5 34.0

(! / min) Oxygen 43.5 43.5 43.5 43.6 43.2 43.5 43.5 44.2 Adhesion time (5 mm) 70 s 60 s 56 s 65 s 55 s 58 s 60 s 72 Extract gas flow ② mixed gas 33.5 33.5 34.0 34.0 34.0 34.0 34.0 34.0 (1 / min) Element 50.1 50.4 52.0 51.5 51.5 52.0 51.4 51.5 Width burning (25mm) 60 seconds 50 seconds 54 seconds 58 seconds 60 seconds 57 seconds 55 seconds 63 seconds

HIS Cracked No None None None None None None None Sagging None None None None None None None None None Metaphysical inspection Flat metallization <1% <1% <1% <1% 1% 1 0%

(J¾,

( ^& , ( ^& )

Tensile test Base material rupture Base material rupture Base material rupture Base material rupture Base material rupture Base material rupture Base material rupture Joint rupture

Out II H

The steel material was subjected to gas pressure welding using a composition in which 5.0 parts by weight of toluene was mixed with 100 parts by weight. The initial pressure welding until the joint is compressed by 5 mm and the supply of heating gas until the joint is compressed by 25 mm are constant throughout, and the ethylene mixed composition is 36.3 liters / min and the oxygen gas is 59.7. Dispensed liters / minute. The contact time was 41 seconds and the sintering time was 58 seconds, for a total of 99 seconds. The results are shown in Table 2 below.

..Ί ί 施 1 2

A gas pressure welding test was performed on the steel material in the same manner as in Example 8, except that a composition in which the types and ratios of the organic compounds shown in Table 2 were mixed with ethylene was used. The results are shown in Table 2.

I 詹 I

The steel material was gas-welded in the same manner as in Example 8 except that only ethylene was used, and the results are shown in Table 2.

Table 2

W, M q ^ JUi or; ifr Example 1 1 Example 1 9 Upper 3 ヒ Example 2 Ethylene UU iL mouth f) UU H mouth p XuU iL Dl> UU £> mouth |) UU iL mouth I) Ρ yes it Additive Toluene 5 parts by weight 2ffi part 2 parts by weight

Octane 4ffl part 2 parts by weight methanol lffi part

Acetone 1 part by weight lffl part force Wi M mixed gas θ. 3 9 ΌΛ o 7 ζ 36.5 34.4 (1 / min) Oxygen 59.7 60.8 60.8 63.1 61.2 57.5 Cohesion time (5mm) 41 seconds 39 seconds 38 seconds 38 seconds 38 seconds 43 Second Width burning time (25mm) 58 seconds 54 seconds 57 seconds 55 seconds 56 seconds 59 seconds Outside S cracked none none none none none none none dripping none none none none none

Fracture surface inspection 1% <1% <1% <1% <1%

Pipi

(&, (&, Ί ^& ) 1 &) 1 &,

Tensile test Base material rupture 1 Base material rupture Base material rupture 1 Base material rupture Base material rupture Joint break

Industrial applicability

The ethylene material mixture composition for gas pressure welding of steel of the present invention is inexpensive and excellent in safety as compared with acetylene, and the use of the ethylene mixture composition does not cause excessive burning of the surface of the steel material. Gas pressure welding of steel with sufficient pressure welding strength is achieved.

Claims

The scope of the claims

1. A steel material comprising ethylene and at least one organic compound selected from the following (1) to (5), wherein the organic compound is 0.1 to 30 parts by weight based on 100 parts by weight of ethylene. Ethylene mixed composition for gas pressure welding.

(1) Hydrocarbons having 5 to 12 carbon atoms

(2) Alcohols with 1 to 12 carbon atoms

(3) Ethers having 2 to 12 carbon atoms

(4) Ketones having 3 to 12 carbon atoms

(5) Esters having 3 to 12 carbon atoms

2. The ethylene composition for gas pressure welding of steel according to claim 1, comprising at least one organic compound selected from ethylene and hydrocarbons having 5 to 12 carbon atoms.

3. The ethylene mixed composition for gas pressure welding of steel according to claim 2, wherein the hydrocarbon having 5 to 12 carbon atoms is an aromatic hydrocarbon.

4. The ethylene mixture composition for steel gas welding according to claim 3, wherein the aromatic hydrocarbon is toluene.

5. The ethylene material mixture composition for gas pressure welding of steel according to claim 1, wherein the organic compound is acetone, methanol or octane.