JP2001073029A - High Cr heat resistant alloy for heating furnace skids - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a high temperature compressive deformation resistance and a high temperature oxidation resistance by incorporating specified amounts of Re and Y in a high Cr heat resistant alloy with a specified composition. SOLUTION: The high Cr heat resistance alloy for a heating furnace skid is constituted by wt.% of 0.1-0.6% C, <=2.0% Si, <=2.0% Mn, 60-85% Cr and further, 0.1-5.0% Re and/or 0.1-5.0% Y and the balance Fe with inevitable impurities. Further, if necessary for improving the high temperature deformation resistance, 5-20% Ni, 5-30% Co, 0.1-5.0% Mo, 0.1-10.0% W, 0.1-1.5% Nb, 0.1-1.5% Zr, 0.1-3.0% Ta, 0.01-1.5% B and 0.01-1.5% Ti and/or 0.1-3.0% V, are contained, and further, for improving the oxidation resistance, 0.1-3.0% Hf and/or 0.01-1.5% Al are contained. This alloy is melted in a high frequency induction furnace and cast into a sand mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high Cr heat resistant alloy for a heating furnace skid.

[0002]

2. Description of the Related Art When a steel material to be heated such as a billet or a slab is transported in a heating furnace, a walking beam conveyor is used. The fixed beam and the moving beam of the walking beam conveyor include a skid rail or a skid button (hereinafter, referred to as "heating furnace skid") 1 which is coated on a skid pipe 3 with a refractory 2 as shown in FIG. Used. This heating furnace skid has 1
Since it is exposed to a high-temperature oxidizing atmosphere exceeding 300 ° C. and carries a heavy heated steel material 4 such as a billet or a slab, it must be made of a material excellent in high-temperature compression deformation resistance and high-temperature oxidation resistance. is necessary.

Hitherto, it has been known to use a high Cr-based heat-resistant alloy for the heating furnace skid, and the following cast or sintered alloy is known as the high Cr-based heat-resistant alloy. A heat-resistant alloy for a heated steel support surface member in a heating furnace, comprising 70 to 80% of Cr, 10 to 15% of Ni, and the balance substantially of Fe (Japanese Patent Application Laid-Open No. 4-31047). Cr: 65 to 80%, Co: 10 to 15%, N: 0.1
Heat-resistant alloy for supporting a steel material to be heated in a heating furnace, the balance being substantially 1.5% to 1.5% with the balance being Fe (JP-A-4-301048).
issue). A heat-resistant alloy for supporting a steel material to be heated in a heating furnace, comprising Cr: 70 to 95%, N: 0.1 to 1.5%, and the balance substantially Fe (Japanese Patent Application Laid-Open No. Hei 4-31049).

Cr: 65 to 80%, Co: 10.1 to 1
5%, Ta or W: 1 to 10%, the balance being substantially Fe
Heat-resistant alloy for a supporting surface member in a heating furnace (Japanese Patent Laid-Open No. 6-2)
No. 065). Cr: 70 to 80%, Ni: 10.1 to 15%, Ta or W: 1 to 10%, balance being substantially Fe, heat-resistant alloy for a supporting surface member in a heating furnace (Japanese Patent Laid-Open No. 6-2066) . C: 0.8% or less, Cr: 60 to 95%, Zr: 0.1
５5%: High Cr heat resistant alloy consisting essentially of Fe (JP-A-7-197178). C: 0.8% or less, Cr: 60 to 95%, B: 0.1 to
2%: High Cr heat resistant alloy consisting essentially of Fe (JP-A-7-197179).

[0005] Cr: 70% or more, Mo: 8% or less, N:
High Cr heat resistant alloy comprising 2000 ppm or less, O: 2000 ppm or less, and the balance substantially composed of Fe
No. 8718). C: 0.8% or less, Cr: 60 to 85% and Ni or C
o: contained 5% or less, and if necessary, W, Mo , N
b, one of Ti and V or two or more containing 10% or less, also one or two of Hf及 beauty Al optionally 1
A high Cr heat resistant alloy containing 0% or less and the balance being substantially Fe (Japanese Patent Application Laid-Open No. 9-227980).

[0006] Cr: 70% or more, Nb: 0.5 to 5%,
W: 0.5 to 5%, N: 2000 ppm or less, O: 20
High Cr heat-resistant alloy consisting of less than or equal to 00 ppm and the balance substantially consisting of Fe (Japanese Patent Application Laid-Open No. 9-235624). Cr: 60% or more, Mo: 0.5 to 8%, W: 5% or less, Nb: 5% or less, N: 2000 ppm or less, O: 2
2,000 ppm or less, with the balance being substantially Cr composed of Fe
Heat-resistant alloy (JP-A-10-226841).

[0007] However, these high Cr heat resistant alloys are alloys which are quite excellent in high-temperature compression deformation resistance and high-temperature oxidation resistance, but have not been sufficient.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high Cr heat resistant alloy for a heating furnace skid which is more excellent in high temperature compression deformation resistance and high temperature oxidation resistance.

[0009]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies on high-temperature compression deformation resistance and high-temperature oxidation resistance of a high Cr heat-resistant alloy. It has been found that the inclusion of Y leads to excellent high-temperature compression deformation resistance (high-temperature compression strength), and that the inclusion of Y in a high-Cr heat-resistant alloy results in excellent high-temperature oxidation resistance. The invention has been made.

That is, the high C for the heating furnace skid of the present invention.
In the heat resistant alloy, C: 0.1 to 0.6%, Si:
2.0% or less, Mn: 2.0% or less, and Cr: 60 to 8
5%, Re: 0.1-5.0% and Y:
0.1 to 5.0% of one or two kinds, the balance being Fe
And inevitable impurities.

Further, high Cr for heating furnace skids of the present invention is provided.
In the heat-resistant alloy, C: 0.1 to 0.6%, Si:
2.0% or less, Mn: 2.0% or less, and Cr: 60 to 8
5%, Re: 0.1-5.0% and Y:
Ni: 5 to 20%, Co: 5 containing 0.1 to 5.0% of one or two kinds and further improving high-temperature compression deformation resistance
-30%, Mo: 0.1-5.0%, W: 0.1-1
0.0%, Nb: 0. 1 to 1.5%, Zr: 0. 1
~ 1.5%, Ta: 0. 1 to 3.0%, B: 0.01
-1.5%, Ti: 0.01-1.5% and V: 0.1
Hf: 0.1% to 3.0% and Al: 0.01% to improve oxidation resistance.
1.5% of one or two kinds, and the balance is made of Fe and unavoidable impurities.

[0012]

Next, the components of the high Cr heat-resistant alloy for a heating furnace skid of the present invention and the reasons for limiting the contents thereof will be described. C: 0.1-0.6%, Si: 2.0% or less A small amount of C and Si moderately lowers the melting point of the alloy while maintaining high-temperature strength and oxidation resistance, thereby causing the flow of the molten alloy. It is an element that improves the resilience and relaxes restrictions during melting and casting, and is included for that purpose. Just C is 0.6
%, When the content of Si exceeds 2.0%, the high-temperature strength,
Deterioration of oxidation resistance and the like.
0.6% and Si is 2.0% or less.

Mn: 2.0% or less Mn is added as a deoxidizing agent at the time of steel production like Si, but if it exceeds 2.0%, the high-temperature oxidation resistance is reduced. The amount is 2.0% or less. Preferably it is 0.4% or less.

Cr: 60-85% High Cr has a high melting point of the alloy (about 1600 ° C.), and has a high-temperature compressive strength and high-temperature oxidation resistance (high-temperature oxidation resistance) in a high-temperature oxidizing atmosphere furnace exceeding 1300 ° C. Improve). To obtain these effects, the content needs to be 60% or more, but if it exceeds 85%, melting and casting become difficult, so the content is set to 60 to 85%.

Re: 0.1 to 5.0% Re has a low diffusion rate in the matrix, contributes to solid solution strengthening, and improves high-temperature compression deformation resistance (high-temperature compression strength). It is an element to be contained. In order to obtain these effects, it is necessary to contain 0.1% or more. However, if the content exceeds 5.0%, the resistance to compression deformation is rather reduced, so that the content is 0.1 to 5.0%. I do.

Y: 0.1-5.0% Y is an element to be included for enhancing the adhesion of the oxide film on the surface of the alloy, preventing cracks and improving high-temperature oxidation resistance. To obtain this effect, the content must be 0.1% or more. However, if the content exceeds 5.0%, the high-temperature oxidation resistance is rather reduced.
5.0%.

Ni: 5 to 20% Ni is an element to be included because it enhances high-temperature rupture and high-temperature oxidation resistance, and also enhances high-temperature compression deformation resistance in the presence of high Cr. To obtain these effects, it is necessary to contain 5% or more.
%, The high-temperature rupture and high-temperature compression deformation resistance are significantly reduced.
%. Co: 5 to 30% Co is an element to be included for enhancing high-temperature compression deformation resistance and high-temperature rupture. To obtain this effect, it is necessary to contain 5% or more, but 30%
When the content exceeds 50%, the resistance to high-temperature rupture and high-temperature compression deformation is greatly reduced.
And

Mo: 0.1-5.0% Mo is an element to be included for increasing the high-temperature strength. To obtain this effect, the content must be 0.1% or more. However, if it exceeds 5.0%, toughness and high-temperature oxidation resistance are reduced.
0%. W: 0.1 to 10.0% W is an element to be contained for generating a solid solution or an intermetallic compound and increasing the high-temperature strength. To obtain this effect, it is necessary to contain 0.1% or more.
If the content exceeds 0.0%, the high-temperature strength and the high-temperature oxidation resistance are rather reduced, so the content is set to 0.1 to 10.0%.

Nb: 0.1 to 1.5%, Ta: 0.1 to 3.0% Nb and Ta form a solid solution or an intermetallic compound similarly to W and increase the high-temperature strength. It is an element to be contained. In order to obtain this effect, it is necessary to contain 0.1% or more. However, if Nb exceeds 1.5% and Ta exceeds 3.0%, the high-temperature strength and the high-temperature oxidation resistance are rather lowered. The amount is 0.1 to 1.5% for Nb and 0.1 to 3.0% for Ta. Zr: 0.1 to 1.5% Zr is an element to be included for improving high-temperature compression deformation resistance and creep rupture strength. In order to obtain these effects, it is necessary to contain 0.1% or more. However, if it exceeds 1.5%, the high-temperature oxidation resistance is reduced, so the content is set to 0.1 to 1.5%. .

B: 0.01 to 1.5% B improves the high-temperature compression deformation resistance and the creep rupture strength similarly to Zr, and is an element to be contained for that purpose. In order to obtain these effects, it is necessary to contain 0.01% or more, but if it exceeds 1.5%, the high-temperature oxidation resistance is reduced, so the content is made 0.1 to 1.5%. . Ti: 0.01 to 1.5%, V: 0.1 to 3.0% Ti and V form solid solutions and intermetallic compounds like W, and increase the high-temperature strength. It is. In order to obtain this effect, it is necessary to contain 0.1% or more. However, if Ti exceeds 1.5% and V exceeds 3.0%, the high-temperature strength and the high-temperature oxidation resistance are rather lowered. The amounts of Ti are 0.01 to 1.5% and V is 0.
1 to 3.0%.

Hf: 0.1-3.0%, Al: 0.01-1.5% Hf and Al are elements to be included for enhancing high-temperature oxidation resistance. To obtain this effect, Hf
It is necessary to contain 0.1% or more of Al and 0.01% or more of Al. However, if Hf exceeds 3.0% and Al exceeds 1.5%, the high-temperature strength is rather reduced. As follows.

The high-Cr heat-resistant alloy for heating furnace skids of the present invention can be used as a casting alloy, and can be usually produced by melting in a high-frequency induction furnace and casting it in a sand mold.

Next, an embodiment of the present invention will be described. High Cr heat resistant alloys having the component compositions of the present invention and comparative examples shown in Table 1 below were melted using a high-frequency induction furnace in an Ar gas atmosphere and cast into a sand mold to obtain a test block having a diameter of 70 mm and a height of 120 mm. Produced. From these test blocks, φ25 mm for high-temperature compression test, height 50 mm, φ for high-temperature oxidation test
10mm, height 50mm, φ8 for high temperature rupture test
Each test piece having a length of 100 mm and a length of 100 mm was cut out. Using these test pieces, a high-temperature compression test, a high-temperature oxidation test and a high-temperature rupture test were tested by the following methods, and the results are shown in the columns of high-temperature compression strength, high-temperature oxidation resistance and high-temperature rupture strength in Table 2 below.

[0024]

[Table 1]

High Temperature Compression Test A cylindrical test piece having a diameter of 25 mm and a height of 50 mm was placed vertically on a fixed table, and heated to 1350 ° C., and a vertical load of about 0.5 kgf / mm ² (approximately 245Kg
f) was added for 50 hours, and its compressive deformation speed was determined. The high-temperature compression deformation rate is determined by setting the height of the test piece before the test to L.
0, height L after test, and deformation ratio D (L0-L)
In the case of / L0 × 100%, it was determined as D / Hr.

High temperature oxidation test φ10 mm, height 50 mm (surface area 0.01585)
7m ² ) The test piece was 135
The mixture was heated to 0 ° C. for 100 hours, and the weight loss due to oxidation was determined. The weight loss by oxidation was expressed as g / m ² · Hr, assuming that the weight of the test piece was W0 before the test and the weight of the test piece after removing the oxide scale was W after the test.

High-Temperature Rupture Test A test piece having a diameter of 8 mm and a height of 100 mm was heated and held at 1250 ° C., and a tensile stress of 1.0 kgf / mm ² (approximately 50 kgf) was applied.

[0028]

[Table 2]

From these results, it is clear that the sample of the present invention has a high-temperature compressive strength of 0.021 to 0.075% / Hr, a high-temperature oxidation resistance of 1.30 to 2.15 g / m ² .Hr, and a high-temperature rupture. While the strength was 53.2 to 164.3 hr, the high temperature compressive strength of the comparative example was 0.068 to
0.082% / Hr, high-temperature oxidation resistance of 1.97 to 2.3
0 g / m ² · Hr and high-temperature rupture strength of 49.1 to 49.1
It was 57.4 hr.

In the example of the present invention, 3,4,6 ~ 8,10
In No. 14, all of the high-temperature compression strength, high-temperature oxidation resistance and high-temperature rupture strength were superior to those of the comparative example. further,
No. of the present invention example. In Comparative Examples Nos. 1 and 5, in which the high-temperature oxidation resistance was higher than that of the content of the present invention, Y was higher than the content of the present invention. Comparative Example N, which is inferior to Comparative Example 3 but has high-temperature compressive strength and high-temperature rupture strength.
o. It was better than 3.

Further, in Example No. of the present invention, 2 and 9 are Comparative Examples N in which the high-temperature compressive strength was higher than the content of the present invention in Re.
o. Comparative Example No. 2 was inferior to high temperature oxidation resistance, though inferior to Comparative Example No.
Better than 2. Comparative Example 1, which does not contain Re and Y, was inferior in all of the high-temperature compressive strength, high-temperature oxidation resistance and high-temperature rupture strength to all of the inventive examples and the other comparative examples. Further, Comparative Example 4 in which the content of Cr was smaller than the content of the present invention was inferior to Comparative Example 1 in all of the high-temperature compression strength, high-temperature oxidation resistance, and high-temperature rupture strength.

[0032]

The high Cr heat resistant alloy for a heating furnace skid according to the present invention contains one or two of Re and Y, and has a higher high-temperature compressive strength and high-temperature oxidation resistance than those not containing these. And the high temperature rupture strength is increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining a skid of a heating furnace using a high Cr heat resistant alloy for a heating furnace skid according to the present invention.

[Brief description of reference numerals]

 DESCRIPTION OF SYMBOLS 1 Heating furnace skid 2 Irregular refractories 3 Skid pipe 4 Heated steel

Claims (12)

[Claims] C .: 0.1 to 1% by weight (the same applies hereinafter)
0.6%, Si: 2.0% or less, Mn: 2.0% or less,
A high Cr heat-resistant alloy for heating furnace skids, comprising 60 to 85% of Cr and 0.1 to 5.0% of Re, with the balance being Fe and unavoidable impurities. 2. C: 0.1-0.6%, Si: 2.0%
Hereinafter, high Cr for heating furnace skids characterized by containing Mn: 2.0% or less, Cr: 60 to 85%, and Y: 0.1 to 5.0%, with the balance being Fe and inevitable impurities.
Heat resistant alloy. 3. C: 0.1-0.6%, Si: 2.0%
Mn: 2.0% or less, Cr: 60 to 85%, R
A high Cr heat resistant alloy for heating furnace skids, comprising e: 0.1 to 5.0% and Y: 0.1 to 5.0%, with the balance being Fe and unavoidable impurities. 4. C: 0.1-0.6%, Si: 2.0%
Hereinafter, Mn: 2.0% or less, Cr: 60 to 85%, and R
e: 0.1 to 5.0%, and Ni: 5 to 20%
%, Co: 5 to 30%, Mo: 0.1 to 5.0%, W:
0.1 to 10.0%, Nb: 0.1 to 1.5%, Zr:
0.1-1.5%, Ta: 0.1-3.0%, B: 0.
01-1.5%, Ti: 0.01-1.5% and V:
A high Cr heat resistant alloy for a heating furnace skid, comprising 0.1 to 3.0% of one or more kinds, and the balance being Fe and unavoidable impurities. 5. C: 0.1-0.6%, Si: 2.0%
Hereinafter, it contains Mn: 2.0% or less, Cr: 60 to 85% and Y: 0.1 to 5.0%, and further Ni: 5 to 20%.
%, Co: 5 to 30%, Mo: 0.1 to 5.0%, W:
0.1 to 10.0%, Nb: 0.1 to 1.5%, Zr:
0.1-1.5%, Ta: 0.1-3.0%, B: 0.
01-1.5%, Ti: 0.01-1.5% and V:
A high Cr heat resistant alloy for a heating furnace skid, comprising 0.1 to 3.0% of one or more kinds, and the balance being Fe and unavoidable impurities. 6. C: 0.1-0.6%, Si: 2.0%
Mn: 2.0% or less, Cr: 60 to 85%, R
e: 0.1 to 5.0% and Y: 0.1 to 5.0%, Ni: 5 to 20%, Co: 5 to 30%, M
o: 0.1 to 5.0%, W: 0.1 to 10.0%, N
b: 0.1 to 1.5%, Zr: 0.1 to 1.5%, T
a: 0.1 to 3.0%, B: 0.01 to 1.5%, T
i: 0.01 to 1.5% and V: 0.1 to 3.0% 1
A high-Cr heat-resistant alloy for a heating furnace skid, comprising one or more kinds and the balance being Fe and inevitable impurities. 7. C: 0.1-0.6%, Si: 2.0%
Hereinafter, Mn: 2.0% or less, Cr: 60 to 85%, and R
e: 0.1-5.0%, and Hf: 0.1-5.0%
High Cr heat resistant alloy for heating furnace skids, containing one or two kinds of 3.0% and Al: 0.01 to 1.5%, with the balance being Fe and unavoidable impurities. 8. C: 0.1-0.6%, Si: 2.0%
Hereinafter, Mn: 2.0% or less, Cr: 60 to 85%, and Y: 0.1 to 5.0%, and Hf: 0.1 to 5.0%
High Cr heat resistant alloy for heating furnace skids, containing one or two kinds of 3.0% and Al: 0.01 to 1.5%, with the balance being Fe and unavoidable impurities. 9. C: 0.1-0.6%, Si: 2.0%
Mn: 2.0% or less, Cr: 60 to 85%, R
e: 0.1 to 5.0% and Y: 0.1 to 5.0%, and Hf: 0.1 to 3.0% and Al: 0.01
A high-Cr heat-resistant alloy for heating furnace skids, characterized in that it contains one or two of 1.5% and the balance is Fe and inevitable impurities. 10. C: 0.1-0.6%, Si: 2.0
%, Mn: 2.0% or less, Cr: 60 to 85% and Re: 0.1 to 5.0%, and Ni: 5-2.
0%, Co: 5 to 30%, Mo: 0.1 to 5.0%,
W: 0.1 to 10.0%, Nb: 0.1 to 1.5%, Z
r: 0.1 to 1.5%, Ta: 0.1 to 3.0%, B:
One or more of 0.01 to 1.5%, Ti: 0.01 to 1.5% and V: 0.1 to 3.0% are contained, and Hf: 0.1 to 3.0%. 0% and Al: 0.01 to 1.5
%, And the balance is Fe and unavoidable impurities. A high Cr heat resistant alloy for heating furnace skids. 11. C: 0.1-0.6%, Si: 2.0
%, Mn: 2.0% or less, Cr: 60 to 85% and Y: 0.1 to 5.0%, and Ni: 5 to 20%
%, Co: 5 to 30%, Mo: 0.1 to 5.0%, W:
0.1 to 10.0%, Nb: 0.1 to 1.5%, Zr:
0.1-1.5%, Ta: 0.1-3.0%, B: 0.
01-1.5%, Ti: 0.01-1.5% and V:
0.1 to 3.0% of one or more kinds.
f: 0.1 to 3.0% and Al: 0.01 to 1.5%, one or two kinds of which are Fe and unavoidable impurities, the balance being high Cr for heating furnace skids. Heat resistant alloy. 12. C: 0.1-0.6%, Si: 2.0
%, Mn: 2.0% or less, Cr: 60 to 85%, R
e: 0.1 to 5.0% and Y: 0.1 to 5.0%, Ni: 5 to 20%, Co: 5 to 30%, M
o: 0.1 to 5.0%, W: 0.1 to 10.0%, N
b: 0.1 to 1.5%, Zr: 0.1 to 1.5%, T
a: 0.1 to 3.0%, B: 0.01 to 1.5%, T
i: 0.01 to 1.5% and V: 0.1 to 3.0% 1
Hf: 0.1 to 3.0%
And Al: a high Cr heat resistant alloy for a heating furnace skid, containing one or two kinds of 0.01 to 1.5%, with the balance being Fe and inevitable impurities.