JPH08294793A - Welding material with high strength, high corrosion resistance and superior welding performance for ferritic steel - Google Patents

Abstract

PURPOSE: To provide such welding material for ferritic steel as superior in welding performance. CONSTITUTION: The material contains 0.03-0.13% C, 0.10-0.80% Si, 8-13% Cr, 0.01-1.30% Ni, 0.005-0.30% Mo, 0.01-0.20% Nb, 0.1-0.5% V, 1.5-4.0 W, 0.5-6.0% Co, 0.005-3.0% Cu, 0.003-0.080% N, 0.01% or less Al, 0.001-0.005% S, 0-0.020% B, 0-0.002% at least one kind from La, Ce and Y, and 0-0.002% either Ca or Mg or both. The welding material with high strength, high corrosion resistance and superior welding performance for ferritic steel is such that P in impurities is 0.025% or less, that relation between Mn and S satisfies the following formula (I) and that relation between Al and O(oxygen) satisfies the following formula (II). (0.0925-12.5[%S])%<=Mn<=2.0%...(I). (Al+O)<=0.02%...(II). Thus, a weld joint can be obtained which is superior in welding performance and which is also provided with sufficient corrosion resistance and high temperature strength.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding material suitable for use in welding high strength, high corrosion resistant ferritic steel used at high temperatures.

[0002]

2. Description of the Related Art As a high temperature material used for heat resistant and pressure resistant piping of boilers, chemical equipment, etc., 2/4 Cr-1
Mo steel, ferritic steel such as 9Cr-1Mo, 18Cr
Austenitic stainless steel represented by -8Ni steel is well known. Among them, ferritic steel is not only cheaper than austenitic stainless steel, but also has excellent stress corrosion cracking resistance. Have.

However, a steel having a so-called ferritic structure such as ferrite, bainite, and martensite has a drawback in that it has a lower high temperature strength than a steel having an austenitic structure.

In recent years, many new stainless steels have been invented which have excellent high temperature strength by adjusting the contents of Mo, W, V, Nb, Al, etc. based on ferritic steel containing 8 to 13% of Cr. (For example, JP-A-62-2
97435, JP-A-63-8256, JP-A-2-232.
345, Japanese Patent Laid-Open No. 3-97832). However, recently, in order to further improve the high temperature strength, W, C
Steels containing a large amount of o have been proposed (for example,
(See JP-A-5-263196, JP-A-5-311344, JP-A-5-311345, and JP-A-6-293940).

Regarding the welding materials required when these new ferritic steels containing W and Co are used as a welded structure, Japanese Patent Laid-Open Nos. 5-177383, 5-177384, 5-212582, and 5-212582, JP-A-6
No. 142981 and Japanese Unexamined Patent Publication (Kokai) No. 7-80680 propose a common metal welding material.
In addition to these common metal welding materials, commercially available welding materials for austenitic stainless steel and Ni alloy may be used.

[0006]

In the case of welding a high strength, high corrosion resistant ferritic steel (for example, the alloy shown in JP-A-6-293940) using the above existing welding material, Such a problem remains.

Japanese Unexamined Patent Publication No. 5-177383 and Japanese Unexamined Patent Publication No. 5-17
7384, JP-A-5-212582, JP-A-6-142
981 and Japanese Patent Application Laid-Open No. 7-80680, when the wire is used, high temperature strength (creep strength, tensile strength) equivalent to that of the base material can be obtained, but Mo is reduced to improve creep strength. .3 to 1.6
%, The toughness is deteriorated and sufficient impact characteristics of the welded portion cannot be obtained.

It does not have sufficient weldability. That is, a weld bead with a uniform bead width that is unlikely to cause welding defects cannot be obtained, and a sufficient back beat cannot be obtained under a wide range of welding conditions.

Further, when a commercially available welding material for austenitic stainless steel and Ni alloy is used, welding hot cracking is likely to occur.

During high-temperature use, C in the base metal migrates to the weld metal (austenitic stainless steel or high Ni alloy) side, and a decarburized layer is formed, which causes cracking or a decrease in creep strength.

An object of the present invention is to provide a welding material which, when welding high-strength, high-corrosion-resistant ferritic steel, imparts high-temperature strength and high-temperature corrosion resistance comparable to the base metal to the welded portion and has excellent welding workability. To provide.

[0012]

The gist of the present invention resides in the following welding material for high strength, high corrosion resistant ferritic steel.

% By mass, C: 0.03 to 0.13%, S
i: 0.10 to 0.80%, Cr: 8 to 13%, Ni:
0.01-1.30%, Mo: 0.005-0.30
%, Nb: 0.01 to 0.20%, V: 0.1 to 0.5
%, W: 1.5 to 4.0%, Co: 0.5 to 6.0%,
Cu: 0.005-3.0%, N: 0.003-0.0
80%, Al: 0.01% or less, S: 0.001 to 0.
005%, B: 0 to 0.020%, La, Ce and Y
At least one of 0 to 0.002% and either or both of Ca and Mg: 0 to 0.002%, the balance consisting of Fe and inevitable impurities, and P in the impurities is 0.025%. Below, the relationship between the contents of Mn and S satisfies the following formula, and the relationship between the contents of Al and O (oxygen) satisfies the following formula, respectively. Welding material for corrosion resistant ferritic steel.

(0.0925-12.5 [% S])% ≦ Mn ≦ 2.0% (Al + O) ≦ 0.02% .. "0%" in the above welding materials means no addition.
Furthermore, desirable conditions are as follows (1) to (4).

(1) Desirable upper limit of Al content is 0.00
9%, and a more desirable upper limit is 0.008%.

(2) When B is contained, a desirable range is 0.001 to 0.020%, and a more desirable range is 0.1%.
0015-0.018%, the most desirable range is 0.0
It is 02 to 0.015%.

(3) The desirable range when at least one of La, Ce and Y is contained is 0.0005 to
0.0020%, more desirable range is 0.0006-
0.0018%, the most desirable range is 0.0008-
It is 0.0015%. However, La, Ce and Y
At least one (hereinafter referred to as rare earth 3 element) and Ca
Alternatively, it is desirable not to perform composite addition with Mg.

(4) When one or both of Ca and Mg are contained, a desirable range is 0.0005-
0.002%, more desirable range is 0.0006-
0.0018%, the most desirable range is 0.0008-
It is 0.0015%.

The present inventors have found the following (a) and (b) in order to solve the above-mentioned problems, and have reached the present invention.

(B) Addition of Mo is indispensable for securing high temperature strength (creep strength), but as a result of studying the effect of Mo content on toughness and creep strength, a large amount of addition was found during use at high temperature. To promote the growth of brittle intermetallic compounds, which not only lowers toughness but also lowers creep strength. That is, there should be an appropriate Mo content range for maintaining both good creep strength and toughness.

(B) S in steel improves the ability to form backside waves (easiness of backside welding), but excessive addition causes instability of the weld pool, and the uniformity of the weld beat (bead width). No change,
(Ease of obtaining uniform weld beads) is deteriorated. Therefore, if the S content becomes excessive, it is impossible to achieve both the back bead forming ability and the uniformity of the weld bead.

As a result of investigating the relationship between the contents of S and Mn, the Mn content is appropriately adjusted according to the S content to enhance the degree of concentration of the arc current without adding S excessively. The ability to increase the penetration depth. As a result, it is possible to easily perform backside welding without deteriorating the uniformity of the weld bead width.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The reason why each component in the welding material according to the present invention is limited as described above will be explained together with its function and effect. % Means mass%.

C: 0.03 to 0.13% C forms a carbide and contributes to the improvement of high temperature strength. Further, it contributes to the suppression of the formation of δ ferrite as an austenite forming element. To obtain this effect, at least 0.0
A C content of 3% is required. On the other hand, the C content is 0.1
If it exceeds 3%, a eutectic with a low melting point is formed with Cr, Nb, and V in the weld metal, causing hot cracking in the weld.

Therefore, the C content range is 0.03 to 0.
It was set to 13%. 0.035 to 0.125 is preferable
%, And more preferably 0.04 to 0.120%.

Si: 0.10 to 0.80% Si is effective in improving oxidation resistance and high temperature corrosion resistance. To obtain this effect, a Si content of 0.10% or more is required. On the other hand, excessive addition of Si content exceeding 0.80% leads to deterioration in toughness.

Therefore, the Si content range is 0.10 to
It was 0.80%. Desirable 0.13 to 0.70
%, And more preferably 0.15 to 0.60%.

Cr: 8 to 13% Cr is a main element constituting stainless steel, and is an essential element for securing oxidation resistance and high temperature corrosion resistance at high temperatures. To obtain this effect, a Cr content of 8% or more is required. On the other hand, if the Cr content exceeds 13%, the toughness decreases.

Therefore, the Cr content range is 8 to 13%. A desirable range is 8.2 to 12.8%, and a more desirable range is 8.5 to 12.5%.

Ni: 0.01 to 1.30% Ni is a necessary element from the viewpoint of suppressing the formation of the δ ferrite phase and ensuring the toughness as a martensite single phase structure. To obtain this effect, a Ni content of 0.01% or more is required. On the other hand, when the Ni content exceeds 1.30%, the austenite transformation temperature (Ac ₁ point) is lowered, and as a result, austenite transformation occurs during post-welding heat treatment,
This causes a decrease in creep strength.

Therefore, the Ni content range is 0.01 to
It was set to 1.30%. 0.02 to 1.28 is preferable
%, And more preferably 0.03 to 1.25%.

Mo: 0.005 to 0.30% Mo is an element that solid-solution strengthens the matrix and precipitates as fine carbides, which contributes to the improvement of creep strength. To obtain this effect, the Mo content needs to be 0.005% or more. On the other hand, when the Mo content exceeds 0.30%, the formation of brittle intermetallic compounds during use at high temperature is promoted, which may lead to a decrease in toughness and a decrease in creep strength.

Therefore, the range of Mo content is 0.005 to
It was set to 0.30%. Desirable 0.008 to 0.2
9%, more preferably 0.01 to 0.28%.

Nb: 0.01 to 0.20% Nb is an element that forms Nb (C, N) and contributes to the improvement of creep strength.

To obtain this effect, 0.01% or more of Nb is used.
Content is required. On the other hand, if the Nb content exceeds 0.20%, the toughness decreases and welding hot cracking occurs.

Therefore, the range of the Nb content is 0.01 to
It was 0.20%. 0.02-0.19 is desirable
%, And more preferably 0.03 to 0.18%.

V: 0.1 to 0.5% V is an element that forms V (C, N) and contributes to the improvement of creep strength. To obtain this effect, V of 0.1% or more
Content is required. On the other hand, when the V content exceeds 0.5%, the toughness is reduced and hot cracking of the weld is caused.

Therefore, the range of V content is 0.1 to 0.5.
%. 0.12 to 0.48% is desirable, and 0.15 to 0.45% is more desirable.

W: 1.5 to 4.0% W is an element that solid-solution strengthens the matrix and precipitates as fine carbide to contribute to the improvement of creep strength. To obtain this effect, a W content of 1.5% or more is required. On the other hand, if the W content exceeds 4.0%, the toughness decreases.

Therefore, the range of W content is 1.5 to 4.0.
%. The desirable range is 1.6 to 3.9%, and the more desirable range is 1.8 to 3.8%.

Co: 0.5 to 6.0% Co is an element that needs to be added from the viewpoint of suppressing the formation of δ ferrite and ensuring toughness as a martensite single-phase structure. To obtain this effect, a Co content of 0.5% or more is required. On the other hand, when the Co content exceeds 6.0%, the austenite transformation temperature (Ac ₁ ) is lowered, and as a result,
Since austenite transformation occurs during post-welding heat treatment, the creep strength decreases.

Therefore, the range of Co content is 0.5-6.
It was set to 0%. A desirable range is 0.7 to 5.8%, and a more desirable range is 1.0 to 5.5%.

Cu: 0.005 to 3.0% Cu has the effect of suppressing the formation of δ ferrite and ensuring toughness. To obtain this effect, 0.005% or more of C
u content is required. On the other hand, if the Cu content exceeds 3.0%, the toughness after long-term use is lowered.

Therefore, the Cu content range is 0.005 to
It was set to 3.0%. 0.007-2.9% is desirable,
More desirable is 0.01 to 2.8%.

N: 0.003 to 0.080% N is an element that combines with Nb and V to form a nitride and contributes to the improvement of creep strength. To obtain this effect, 0.
A N content of 003% or more is required. On the other hand, when the N content exceeds 0.080% and becomes excessive, coarsening of precipitates is caused, and the creep strength is rather deteriorated.

Therefore, the range of N content is 0.003 to
It was set to 0.080%. Desirable is 0.004 to 0.
078%, more preferably 0.005-0.075
%.

Al: 0.01% or less Al is an element added as a deoxidizing agent. The extreme lowering of the Al content lowers the cleanliness of the steel and increases the manufacturing cost, so the lower limit is not specified. On the other hand, if the Al content exceeds 0.01%, the generation of slag in the molten pool is promoted and the flowability of the weld metal is deteriorated. Therefore, A
The 1 content was 0.01% or less. A desirable upper limit is 0.
009%, and a more desirable upper limit is 0.008%.

S: 0.001 to 0.005% S is an element effective for affecting the convection in the molten pool, increasing the penetration depth, and improving the backside wave forming ability.
However, when the content of S exceeds 0.005%, the stability of the arc is deteriorated, and on the contrary, it becomes a cause of deterioration of the welding workability.
On the other hand, if the S content is less than 0.001%, the manufacturing cost increases.

Therefore, the range of S content is 0.001 to
It was set to 0.005%. Desirable 0.0012-
0.0049%, and more preferably 0.0015-0.
It is 0048%.

P: 0.025% or less P is an unavoidable impurity, and the lower the better, the more preferable it is. However, an extremely low P causes a great increase in cost. On the other hand, if the P content exceeds 0.025%, heating embrittlement of the weld metal is caused. Therefore, the P content is 0.025
% Or less. A desirable upper limit is 0.023%, and a more desirable upper limit is 0.020%.

In the welding material of the present invention, it is particularly necessary to limit Mn and (Al + O) to the following ranges.

Mn: (0.0925-12.5 [% S])% ≤ Mn ≤ 2.0% ··· Formula Mn is the uniformity of the welding beat by adjusting its content by the S content. Without increasing the degree of concentration of the arc current, the rear wave forming ability is improved.
To obtain this effect, the lower limit of the Mn content is [0.092
5-12.5 (% S)]% is required. But,
An excessive addition of Mn content exceeding 2.0% causes embrittlement of the weld metal portion, so the upper limit was made 2.0%. A desirable upper limit is 1.9%, and a more desirable upper limit is 1.8%.

Al + O (oxygen): 0.02% or less (formula) O is combined with Al during welding, and (Al + O) is 0.02%.
If it exceeds, a large amount of slag is generated to deteriorate the flowability of the weld metal. Therefore, the content of O is limited so that (Al + O) is 0.02% or less.

In the welding material of the present invention, in addition, at least one of the following B and rare earth 3 elements (Y, La, Ce) is further added.
A seed, or Ca or Mg can be selected and contained, and their composite addition is also allowed.

B: The upper limit is 0.020%. When B is contained in a small amount, it disperses and stabilizes the carbide and contributes to the improvement of creep strength. Therefore, it is included when it is desired to positively obtain this effect. However, when the B content is 0.
If it is less than 001%, the above effect cannot be obtained. on the other hand,
If the B content exceeds 0.020%, the hot workability is impaired.

Therefore, when B is contained, the content range is 0.001 to 0.020%. What is desirable is
0.0015 to 0.018%, more preferably 0.0
It is 02 to 0.015%.

At least one of the rare earth 3 elements: the upper limit is 0.0020%. Any of the rare earth 3 elements (Y, La, Ce) reduces the weld hot cracking susceptibility of the weld metal. For this reason,
When positively obtaining this effect, at least one kind is selected and contained. However, its content is 0.0005%
If it is less than the above, the above effect cannot be obtained. On the other hand, if the content exceeds 0.0020%, the weldability is impaired.

Therefore, when at least one of the three rare earth elements is contained, the content range is 0.0005 to 0.00.
20%. Desirable range is 0.0006-0.00
18%, more desirable range is 0.0008 to 0.001
5%.

One or both of Ca and Mg: the upper limit is 0.002% Both Ca and Mg contribute to the improvement of hot workability when processing into a wire rod which is a welding material (wire). Therefore, in order to positively obtain this effect, either one or both are contained. However, its content is 0.00
If it is less than 05%, the above effect cannot be obtained. On the other hand, if its content exceeds 0.002%, the cleanliness of the weld metal is reduced.

Therefore, when one or both of Ca and Mg is contained, the content range is 0.0005 to
It is 0.002%. Desirable range is 0.0006-
0.0018%, more desirable range is 0.0008-
It is 0.0015%.

As described above, the welding material of the present invention is
In welding materials made of ferritic stainless steel, Mo
It is characterized in that the content of Mn is regulated within a predetermined range, while a predetermined amount of Cu is added and contained, and the contents of Mn, Al, S and O are regulated within a specific range. The welding material of the present invention can be manufactured by a conventional industrial stainless steel manufacturing method. For refining, a melting method using an electric arc furnace, an AOD (argon-oxygen deoxidation) method,
The VOD (vacuum oxygen decarburization) method is suitable.

For example, in order to reduce S (desulfurization), it is effective to perform desulfurization treatment in a step before decarburization. Also,
In order to keep the Al and O contents within the range of the present invention, it is effective to perform a vacuum treatment on the molten steel whose components have been adjusted to have a predetermined chemical composition and improve the component adjustment accuracy of these elements. . The molten steel having the adjusted composition is cast into a slab (billet) or an ingot by a continuous casting method or an ingot casting method. From this slab or ingot,
A wire rod is formed by hot rolling, and this is used as it is or after cold drawing, and then used as a welding material (wire).

[0063]

EXAMPLE While a test steel pipe having the chemical composition shown in Table 1 was provided with a groove having the shape and dimensions shown in FIG. 1, butted at a root interval of 2 mm, various welding materials (wires having the chemical composition shown in Tables 2 and 3) ) Was used to perform multi-layer circumferential welding of 10 layers by the TIG welding method.

[0064]

[Table 1]

[0065]

[Table 2]

[0066]

[Table 3]

The test steel pipe has an outer diameter of 200 mm and a thickness of 20.
mm, and the creep strength at 600 ° C. for 100,000 hours is 15 kgf / mm ^{2 and is made} of high-strength, high-corrosion-resistant ferritic steel. All of the welding materials used were cotton materials with an outer diameter of 2.4 mm produced by the processes of melting, hot working, and wire drawing.

The welding conditions were set so that the heat input was 25,000 J / cm. Further, after welding, post heat treatment was performed at 760 ° C.

The welding workability was evaluated by measuring the bead fluctuation width of the final layer after welding and measuring the uniformity of the weld beads.
The evaluation criteria were that the variation width of the welding bead was 2 mm or less, and the variation was larger than that.

Further, the ratio of the length of the backside wave formed to the total length of the weld line was measured to evaluate the backside forming ability. The evaluation criteria was that the backside wave formation rate was 100%, and when it was less than 100%, it was disapproved.

Next, a side bending test piece having a length of 60 mm, a width of 5 mm and a thickness of 30 mm, a length of 55 mm, a width of 10 mm, a thickness of 10 mm and a Charpy impact test piece having a V notch of 2 mm so as to include the welded portion in the center portion. , Total length 70mm, gauge length 3
A creep test piece having a diameter of 0 mm and a parallel portion diameter of 6 mmφ and a corrosion resistance test piece having a length of 40 mm, a width of 10 mm and a thickness of 2 mm were sampled and subjected to each test.

In the side bending test, bending was performed at a bending radius of twice the plate thickness by 180 °, and the presence or absence of hot cracking in the weld metal was examined.

In the Charpy impact test and the creep test, the Charpy impact test at 0 ° C. and the creep test at 650 ° C. were performed, respectively.

In the creep test, the high-strength ferritic steel as a base material has a breaking life of about 3000 hrs of 12 kgf.
The test was performed under the condition of / mm ² to determine the creep rupture life of the weld metal. Evaluation shows that creep rupture life is 2400 h
A value of r or more was judged as good, and a value of shorter than that was judged as no.

In the corrosion resistance test, 700 ° C. in water vapor, 1
After heating for 000 hours, the scale thickness of the surface was measured to evaluate the high temperature oxidation resistance as a boiler material.

The above test results are shown in Tables 4 and 5.
The scale thickness in the steam oxidation test of the test base material alone was about 90 μm.

[0077]

[Table 4]

[0078]

[Table 5]

As is clear from Tables 4 and 5, welding materials (Nos. A1 to A) having a chemical composition within the range defined by the present invention are used.
18) Welded joints (No. AJ)
1 to AJ18), the variation width of the weld bead was 2 mm or less, the weld bead width was excellent in uniformity, and the back bead was formed over the entire weld line. As a result, it was confirmed that the welding material of the present invention has excellent weldability and that the welded joint has creep strength, steam oxidation resistance and high toughness comparable to those of the base metal.

On the other hand, welded joints (No. B1 to B22) having a chemical composition outside the range defined by the present invention (No.
BJ1 to BJ22) were not found to have both sufficient weldability and joint performance.

That is, a joint using No. B1 (No. B
In J1), C and Nb are 0.137% and 0.2, respectively.
2%, which exceeds the upper limit defined in the present invention and is excessively contained, so that welding hot cracking occurred. A joint using No. B2 (V. 0.52%, which exceeds the upper limit specified in the present invention) (No. BJ
In 2), welding hot cracking occurred.

In the joint using No. B3 (No. BJ3), Cr was 7.8%, which was below the lower limit specified in the present invention, so the scale thickness in the steam test was 115 μm and the steam oxidation resistance was low. Inferior to In addition, in the joint using No. 4 (No. BJ4), since Si is 0.05%, which is below the lower limit specified in the present invention, the scale thickness in the steam test is 113 μm, and the steam oxidation resistance is low. inferior.

Joints using No. B5 and B6 (No. B
In J5 and BJ6), Mo is 0.308 each.
% And 0.319%, the 0 ° C Charpy impact values are 24 J / cm ² and 28 J / cm, respectively.
^{It was 2} , and neither of them had sufficient toughness. Further, in the joints (No. BJ7 and BJ8) using No. B7 and B8, Mn was 2.10% and 2.12, respectively.
Since% and are included in excess, 0 ° C. Charpy impact value respectively ^{22J / cm 2, 25J / cm} 2 , and the both sufficient toughness can not be obtained.

In the joint using No. B9 (No. BJ9), since W was excessively contained as 4.11%, the Charpy impact value at 0 ° C. was 25 J / cm ² , and No. BJ
In the joint using No. 10 (No. BJ10), Co is 0.4
%, The δ ferrite was precipitated, and the Charpy impact value at 0 ° C. was 27 J / cm ² , and sufficient toughness was not obtained in any case.

Joints using No. B11 and B12 (N
o. BJ11 and BJ12), Mo was too small as 0.002% and 0.003%, respectively, and therefore sufficient creep strength could not be obtained. Also, No. B
In the joint using No. 13 (No. BJ13), Ni is 1.3
Since it was contained in excess of 3%, austenite transformation occurred due to heat treatment after welding, and sufficient creep strength could not be obtained.

Joint using No. B14 (No. BJ14)
However, since W was too small as 1.48%, sufficient creep strength could not be obtained. Joint using No. B15 (N
o. BJ15), since Co was 6.2%, which was excessive, austenite transformation occurred due to heat treatment after welding, and sufficient creep strength could not be obtained.

Joints using No. B16 and B17 (N
BJ16 and BJ17), S is 0.
Since the excess was 0052% and 0.0058%, the fluctuation range of the weld bead was 2.4 mm and 2.8 mm, respectively, and both were inferior in weldability. Further, in the joint (No. BJ18) using No. B18, (Al + O) was 0.
Since the content was excessive at 022%, the molten metal flow was deteriorated, the fluctuation range of the welding bead was 2.2 mm, and the weldability was poor.

Joints using No. B19 and B20 (N
o. BJ119 and BJ20), (0.0092
5-[% S]) is 0.0775, 0.0325, respectively
On the other hand, since Mn was 0.07% and 0.02%, which were too small, the backside wave formation rates were 75% and 90%, respectively, and the weldability was poor.

Joint using No. B21 (No. BJ21)
Since Cu was too small as 0.003%, the 0 ° C. Charpy impact value was 32 J / cm ² and sufficient toughness was not obtained. In addition, a joint using No. B22 (No. BJ2
In 2), since Cu is 3.07%, which is excessive, 600
0 ° C Charpy impact value after aging treatment at ℃ × 300hr is 1
At 0 J / cm ² , the toughness after long-term use was low.

[0090]

INDUSTRIAL APPLICABILITY The welding material of the present invention is excellent in workability during welding of high-strength, high-corrosion-resistant ferritic steel, and by using this material, a welded joint having sufficient corrosion resistance and high-temperature strength can be obtained. It is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing the shape and dimensions of a welding groove used in Examples.

Claims (1)

[Claims] 1. C: 0.03 to 0.13% by mass% and S
i: 0.10 to 0.80%, Cr: 8 to 13%, Ni:
0.01-1.30%, Mo: 0.005-0.30
%, Nb: 0.01 to 0.20%, V: 0.1 to 0.5
%, W: 1.5 to 4.0%, Co: 0.5 to 6.0%,
Cu: 0.005-3.0%, N: 0.003-0.0
80%, Al: 0.01% or less, S: 0.001 to 0.
005%, B: 0 to 0.020%, La, Ce and Y
Of at least one of: 0 to 0.002% and either or both of Ca and Mg: 0 to 0.002%, the balance consisting of Fe and inevitable impurities, and P in the impurities is 0.025%. Below, the relation between the contents of Mn and S satisfies the following formula, and the relation between the contents of Al and O (oxygen) satisfies the following formulas, respectively. Welding material for corrosion resistant ferritic steel. (0.0925-12.5 [% S])% ≦ Mn ≦ 2.0% (Al + O) ≦ 0.02%