Iron-based corrosion resistant wear resistant alloy and deposit welding material for obtaining the alloy

Abstract

To provide a high-performance, inexpensive low C-high Si-high Cr—B—Nb type iron-based corrosion-resistant and wear-resistant alloy that is extremely superior in corrosion resistance and wear resistance to 304 stainless steel, high-chromium cast iron and high carbon-high chromium cast-iron-type materials, has a high corrosion-resistant property that would never be obtained from a high carbon-high chromium carbide precipitation-type iron-based wear-resistant alloy and at the same time, a wear-resistant property that is superior to these metals, and further hardly causes brittle peeling that is inherent to high Si—containing steel. This alloy contains, all percentages by weight, C: 0.5 to 2.5% by weight, Si: 2.5 to 4.5%, Mn: 0 to 10% or less, Cr: 15% to 31%, Ni: 0 to 16%, Cu: 7% or less, Mo: 10% or less, B: 0.5% to 3.5%, and 0≦Nb+V≦8%, and in this structure, within a range of 15% Cr≦Cr<27%, (Si×B)≦2014 / Cr2+0.083Cr+1.05 is satisfied, within a range of 27%≦Cr≦31%, 1.25%≦(Si×B) 6.0% is satisfied, within a range of 15%≦Cr<20%, (Si×B) 570 / Cr2−0.066Cr+1.145 is satisfied, and within a range of 20%≦Cr≦31%, (Si×B)≧1.25 is satisfied.

Description

TECHNICAL FIELD[0001]The present invention relates to a low carbon-high silicon-boron-niobium-high chromium cast steel-type iron-based alloy that is superior in corrosion resistance and wear resistance, more specifically, to a high performance and inexpensive iron-based corrosion-resistant and wear-resistant alloy that is overwhelmingly superior in a corrosion-resistant property and wear-resistant property in comparison with those of 304 stainless steel, high-chromium cast iron, and high carbon-high chromium cast-iron-type material, has a high corrosion-resistant property that would never be obtained from a high carbon-high chromium carbide precipitation-type iron-based wear-resistant alloy and at the same time a wear-resistant property that is superior to that of these metals, and further hardly generate brittle peeling that is inherent to a high-Si content steel, and a clad (hard-surfacing) welding material used for obtaining the same.BACKGROUND ART[0002]In recent years, refuse in...

AI Technical Summary

Benefits of technology

The present invention aims to provide an iron-based alloy that has low carbon content, high corrosion resistance, and wear resistance properties. To achieve this, the inventors have developed a new alloy that combines a large amount of chromium and a small amount of silicon, molybdenum, copper, and niobium. This alloy has been found to have superior properties compared to existing corrosion-resistant and wear-resistant alloys. Additionally, the invention provides a cladding material that can be used for improving corrosion resistance and wear resistance in various applications.

Problems solved by technology

However, in a short period of time after the start of these operations, those members and devices are worn, burnt to be lost, and subjected to corrosive loss by the treated matters and heat, and there have been strong demands for prolonging the service life thereof.

However, these furnace devices and peripheral devices are exposed to such as high-temperature corrosive burning gases and acid dew-point corrosion that occurs upon stopping the furnace, and at present, it becomes difficult to deal with these conditions only by using simple high-temperature oxidation resistant property and wear-resistant property.

That is, unless a superior corrosion-resistant property is also provided, with a superior wear-resistant property possessed by the high carbon-high chromium cast iron-type clad welding material being maintained, it becomes difficult to prolong the service life of these various devices.

However, this alloy is very expensive in comparison with the iron-based alloy, failing to satisfy the cost-effectiveness balance.

Then, at present, since the high carbon-high chromium cast-iron-type clad welding material is inexpensive, this has been continuously used in most cases as the iron-based wear-resistant alloy; however, the corrosion-resistant property thereof is extremely inferior to that of cobalt- and nickel-based materials, and this is hardly called as a corrosion-resistant material.

However, since this has a carbon content that is extremely high, it can be said that the corrosion resistance is not sufficient.

Upon reviewing alloy elements contained in these cobalt-based alloys, it is found that large amounts of cobalt, tungsten and the like are contained so that these alloys are composed of very expensive elements.

Therefore, since the cobalt-based alloys are very expensive alloys, these do not become profitable when applied to a device having a very wide cladding area from the viewpoint of costs, and it is very difficult to satisfy the cost-effectiveness.

For this reason, the use of this alloy is considered to be limited only to applications in which a cladding process on a portion having an extremely limited small area can exert a great effect.

However, the greatest defect of the high Si-containing steel is to make the alloy extremely brittle, and because of this defect, a large amount of addition thereof to an iron-based wear-resistant cladding metal has been avoided even at present.

Incidentally, although a high Si-containing steel referred to as “Silicolloy” has already been produced, this metal was an alloy developed for use in wear-resistant purposes between metals, and its carbon content was in a level of 1 / 100 so that the amount of precipitation of carbides that give a wear-resistant property was extremely small, failing to be practically used in severely high-temperature grinding wear-resistant applications, as in the case of the application of the patented alloy (Patent Document 2).

The deposited metal of a high Si-containing steel has a characteristic of causing slice-shaped surface layer peeling on the surface layer, with the result that, upon carrying out a bending process thereon, there is a fear of scattering of slice-shaped portions.

Without satisfying this correlation formula, a sufficient precipitation of needle-shaped chromium carbides (Cr7C3) is not available, resulting in degradation of the high-temperature wear resistance.

However, the superior characteristic at high temperatures in contrast becomes a serious defect in its brittleness at normal temperature, and the extreme brittleness causes degradation of the bending processability, and when a wear-resistant steel plate cladded with the patented alloy is produced, the resulting product can be only applied to linear items, and with respect to items having a curvature, cladding processes need to be carried out by using a welding wire or a hand welding rod, always resulting in high production costs.

As described above, although the patented alloy can provide performances that are almost equivalent to the stellite alloy, its greatest defect is that the high Si-content easily causes slice-shaped peeling on the surface layer of the deposited metal, making it difficult, in particular, to produce a wear-resistant steel plate having a large area.

Moreover, upon carrying out a join-welding process between clad steels formed by using the same alloy, the hardened metal causes peeling when stretched by a welding stress, making it very difficult to carry out the join-welding process.

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