JPH03232945A - Heat resisting alloy and skid rail using same - Google Patents

Abstract

An oxide-dispersion strengthened type heat-resistant alloy is provided for use in preparing furnace members such as a skid rail. The alloy consists essentially of up to 0.2% C + N, up to 2.0% Si, up to 2.0% Mn, 25 to 35% Ni and 20 to 35% Cr, 5 to 50% Co; and one or more of 0.5 to 5% Mo, 0.5 to 5% W, and 0.2 to 4% Ta, and the balance of Fe, and contains 0.1 to 2% of fine particles of high melting point metal oxide such as Y2O3 dispersed in the austenite matrix. The alloy exhibits excellent properties against hot deformation, also oxidation resistance, abrasion resistance and thermal shock resistance.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a heat-resistant alloy with excellent strength and corrosion resistance at high temperatures. The alloy of the present invention is suitable as a material for skid rails used, for example, in billet heating furnaces in the steel industry.

[Conventional technology]

Generally, steel plates and steel wire rods are manufactured by uniformly heating and rolling steel pieces such as blooms, slabs, and billets in a heating furnace such as a walking beam furnace or a pusher furnace. If the temperature of the portion of these pieces of steel that is in contact with the hearth hardware in the heating furnace is lower than the temperature of other portions, the rolled steel material may have uneven thickness or cracks. In order to prevent this, it is necessary to bring the temperature of the part of the hearth hardware in contact with the heated object close to the soaking temperature of the heated object. Therefore, the maximum operating temperature for hearth hardware is 13
Reaching high temperatures of 00°C or higher. Conventionally, typical examples of hearth metal materials that can withstand high temperatures of 1150°C or higher include Fe, Or: 20-35%, Ni: 1
5-35%, Co: 5-50% as the main component, and other solid solution strengthening elements: Mo: 0° 5-5%, W: 0.5-5
%, Ta: 0.2-4°0% solid solution strengthened heat-resistant cast alloys have been used. However, the skid rail in the soaking zone of the heating furnace is 1200-13
It is exposed to high temperatures of 50°C and is subject to severe deformation and wear. The solid solution strengthened heat-resistant cast alloy described above is unsatisfactory as a material for skid rails. It has been proposed to use ceramics as a material for hearth hardware with high heat resistance and wear resistance (for example, Utility Model Publication No. 55-353268). However, another property required for skid rails is impact resistance. Fine ceramic materials, such as Si, are preferable from the viewpoint of
When C or Si3N4 is used in a strongly oxidizing atmosphere,
Easily damaged by oxidation. On the other hand, oxide dispersion strengthened superalloys, which are strengthened by dispersing fine particles of high melting point oxides such as the Ni-based superalloy Y2O3, are used in gas turbines and jet engines. (For example, Japanese Patent Publication No. 56-38665). For high temperature furnaces, 12°5-20% Cr, 1% or less A, Il
, up to 0.1% C and up to 0.5% (by volume) Y2
It has been proposed that an oxide dispersion strengthened superalloy consisting of O3 and the balance Ni be used as a material for mesh belts (
Special Publication No. 59-9610).

Claims (3)

[Claims] (1) C+N: 0.2% or less, Si: 2.0% or less, M
n: 2.0% or less, Ni: 15 to 35%, Cr: 20 to
In addition to 35 and Co: 5-50%, Mo: 0.5-50%
5.0%, W: 0.5-5.0 and Ta: 0.2-4
．． An oxide dispersion-strengthened heat-resistant alloy containing 0.1 to 2% of fine high-melting point metal oxides dispersed in an austenite matrix of an alloy containing 0% of one or more of the above, and the remainder substantially consisting of Fe. . (2) The heat-resistant alloy according to claim 1, wherein the high melting point metal oxide is Y_2O_3. (3) A skid rail using the heat-resistant alloy according to claim 1 or 2.