JPH01132732A - Corrosion-resisting ni-cr alloy excellent in bendability - Google Patents

Abstract

PURPOSE:To obtain the title Ni-Cr alloy having superior corrosion resistance and bendability by providing a composition which consists of respectively prescribed amounts of Cr and Mo or/and W and the balance Ni and in which respective contents of C and N as inevitable impurities are specified. CONSTITUTION:An Ni-Cr alloy having a composition consisting of, by weight, 38-50% Cr, 0.1-2% Mo or/and W, and the balance Ni with <=0.05% C and 0.04% N as inevitable impurities is provided. This Ni-Cr alloy has superior formability as well as corrosion resistance and, accordingly, this Ni-Cr alloy can be extremely easily formed into various members requiring corrosion resistance without causing the occurrence of cracks, etc., and further, it can stably show extremely superior corrosion resistance over a long period at the time of practical use.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention has excellent corrosion resistance and bending workability, and is therefore suitable for use with corrosive liquids such as pickling tanks, acid recovery equipment, and acid-using dissolution equipment. The present invention relates to a Ni-Cr alloy suitable for use as a structural member in various devices, especially in parts exposed to corrosive liquids, and as a deposition prevention plate in chemical vapor deposition devices, which are often subjected to cleaning treatment to remove deposited materials. It is something.

[Conventional technology]

The same applicant previously developed a Ni--Cr alloy containing 35 to 85% by weight of Cr, as disclosed in Japanese Patent Publication No. 17247/1983, as a material exhibiting excellent corrosion resistance in the above-mentioned corrosion field.

[Problem to be solved by the invention]

However, although the above-mentioned conventional Ni-Cr alloys exhibit excellent corrosion resistance, they do not necessarily have good formability, especially bending workability, and therefore require a considerable number of man-hours for forming when applied to various fields. The current situation is that not only is the reliability of this method not only satisfactory, but also that it is not completely satisfactory in terms of reliability.

[Means to solve the problem]

Therefore, from the above-mentioned viewpoint, the present inventors focused on the conventional Ni-Cr alloy with a high Cr content, and developed a material that has corrosion resistance equivalent to that of the conventional Ni-Cr alloy and has excellent forming processability. As a result of research, it was found that Cr: 38 to 46% (preferably Cr: 43 to 46%) should be developed.
%), one or two of Mo and W: 0.1 to 2%, and if necessary, (i) Cu: 0.1 to 2%, (II) Ca: 0 .001~0.01%, (j
ii) One or more of Zr, Nb, Ta and Hl': 0.1 to 3%, (Iv) One or more of Y and rare earth elements: o, oot~0, 01%, containing one or more of the above (+) to (1v), with the remainder consisting of Ni and inevitable impurities,
and the content of C and N components as unavoidable impurities: C: 0.05% or less, N: 0.04% or less,
It was found that the Ni-Cr alloy obtained by the above method has corrosion resistance and maintains formability.

This invention was made based on the above knowledge, and the reason why the component composition was limited as described above will be explained below.

(a) CrC component has the effect of improving corrosion resistance against various corrosive liquids, but if its content is less than 38%, the desired corrosion resistance cannot be secured; on the other hand, if its content is less than 50%
If it exceeds this amount, it becomes brittle, cracks occur during molding, and crystals form, so the content was set at 38 to 50%.

However, the content of the C component is preferably 38 to 47%, most preferably 43 to 47%, and in this composition range, if the area ratio of precipitation of the Cr-based α phase is 10% or less, the maximum corrosion resistance can be achieved. Therefore, it is possible to obtain good workability.

(b) Mo and W These components include Cr, which is both dissolved in the base material.

Mo and W have the effect of further improving corrosion resistance when they coexist, but if their content is less than 0.1%, the desired excellent corrosion resistance cannot be secured; If it exceeds the content, the molding processability will be significantly lowered, so the content was set at 0.1 to 2%.

(c) Cu The Cu component, together with Cr, Mo, and W, has the effect of improving the corrosion resistance of the alloy, but if the Cu content is less than [1.1%, the desired effect cannot be obtained; Since no further improvement in effectiveness was observed even if the content exceeded 0.1% to 2%.

(d) Ca The Ca component has the effect of improving the deoxidizing and desulfurizing effects during alloy melting, but if the content is less than 0.001%, the desired effect cannot be obtained; The amount is 0.
If the content exceeds the old content, it becomes brittle and cracks are likely to occur during molding, so the content was set at 0.001 to 0.01%.

(e) Zr, Nb, Ta, and H: These components have the effect of further improving the workability of the alloy, but if their content is less than 0.01%, the desired effect cannot be obtained. On the other hand, even if the content exceeds 3%, no further improvement in effectiveness is observed, so the content was set at 0.1 to 3%.

(r) y and rare earth elements These components have the effect of improving the workability of the alloy, but if their content is less than 0.001%, the desired effect cannot be obtained; is 0. (Even if the content exceeds 11%, no further improvement in effectiveness is seen, so
Its content was determined to be 0.001 to 0.01%.

(g) C and N Generally, this type of high Cr content Ni-Cr alloy is
When melting is performed in the atmosphere using a high frequency furnace, which is a normal melting method, even if the raw materials to be melted are carefully selected, the content of C and N components as unavoidable impurities is C: 0.
．． 0.06% or more, N: 0.05% or more, and Ni-Cr alloys with such a high content of C and N as unavoidable impurities have poor formability, especially bending workability. Cracking occurs with slight bending.

However, when this Ni-Cr alloy is double melted using, for example, a vacuum melting method and an electroslag melting method, C:
0.05% or less, N: 0.04% or less, and the formability of Ni-Cr alloys with reduced C and N contents as unavoidable impurities has been dramatically improved. From this point of view, C and N containing melon as unavoidable impurities are reduced to C: 0.05% or less and N: 0.04% or less, respectively, and excellent moldability is achieved. In particular, it is designed to ensure bending workability.

Furthermore, the content of C and N components is C: 0, respectively.
．． It is most preferable to reduce N to 0.01% or less, and by reducing the formation of carbides and nitrides, corrosion resistance can be further improved.

The Ni-Cr alloy of the present invention contains other unavoidable impurities such as Fc: 0.3% or less, Mn: 0.3% or less, TJ: 0.3% or less, and Ag: 3% or less. , and Mg: 05% or less.

〔Example〕

Next, the alloy of the present invention will be specifically explained using examples.

First, a molten alloy with a predetermined composition is prepared using a high-frequency vacuum melting furnace, and then cast into a mold with a diameter of 60 mm and a length of 2 mm.
This ingot was then remelted using an electroslag melting device to obtain an ingot with a diameter of 100 mm having the component composition shown in Table 1.
After homogenization treatment under the conditions of holding at a predetermined temperature within the range of ~1250°C for 10 hours, the same <1150 ~ 1250°C
Hot forging and hot rolling are performed at a predetermined hot working start temperature within the range of 1100 to 1200 °C to obtain a hot rolled plate with a thickness of 4 mm. After homogenizing under the condition of holding the temperature for 30 minutes, cold rolling was performed to obtain a cold rolled sheet with a thickness of 2 mm, and this cold rolled sheet was again rolled at 1100 mm.
By performing homogenization treatment under the condition of holding at a predetermined temperature within the range of ~1200°C for 30 minutes, the alloy sheet material 1~
No. 54 and comparative alloy sheet materials 1 to 12 were manufactured, respectively.

In addition, comparative alloy sheets 1 to 12 all have one of the constituent components as ff1 (the system content is added in Table 1).
has a composition outside the scope of this invention.

Next, for the purpose of evaluating the formability, especially the bending workability, of the obtained alloy sheets 1 to 54 of the present invention and comparative alloy sheets 1 to 12, the tensile elongation at room temperature was measured by i'lFJ.
At the same time, we conducted a 180° bending test based on JIS standards to determine whether or not cracks would occur in the bent part.
-1, and those that could be bent in close contact were further subjected to a close bending test in the opposite direction, and the presence or absence of cracks at the bent portion was observed.

Based on the above JIS current standard, the <180" close bending test means bending the alloy plate 1 shown in FIG. 1(a) as shown in FIG. 1(b) so that one side is brought into close contact with the This is a test to observe whether or not cracks occur.

In addition, in the above-mentioned reverse close bending test, as shown in FIG. This is a harsh test to check for the presence or absence of

Table 1 shows the results of the 180' closed tube bending test and the reverse tight bending test. "Presence or absence of cracking" in Table 1
An X mark in the column indicates that a crack occurred before the close bending process was completed, making close bending impossible, and an O mark indicates that a close bending process was possible, but a crack occurred during close bending in the opposite direction. , ◎ indicates that no cracking occurred even when the specimen was bent in the opposite direction.

Furthermore, for the purpose of evaluating corrosion resistance, temperature: 17% of 60℃
Mixed acid immersion test of immersion in HNO3-3% HF aqueous solution for 24 hours and 8% HCI)-55% at the same temperature = 60 °C
A reverse water immersion test of immersion in an HNO3 aqueous solution for 240 hours was conducted to measure the amount of corrosion. These-Illll
The fixed nodules are shown in Table 1.

〔Effect of the invention〕

From the results shown in Table 1, the alloy sheets 1 to 54 of the present invention all exhibit excellent corrosion resistance and extremely excellent bending workability, whereas the comparative alloy sheets 1 to 12 Furthermore, it is clear that if the amount of any of the constituent components is outside the scope of the present invention, at least one of the corrosion resistance and bending properties will be inferior.

As mentioned above, the Ni-Cr alloy of the present invention has excellent moldability in addition to corrosion resistance, so it can be molded into various parts that require corrosion resistance without cracking or the like. It is easy to carry out, and in practical use, it stably exhibits extremely excellent corrosion resistance over a long period of time, making it highly reliable and has industrially useful properties.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(c) are schematic diagrams showing a test method for evaluating the bending workability of an alloy plate. 1...Alloy plate

Claims (1)

[Claims] (1) Contains 38 to 50% Cr, 0.1 to 2% of one or two of Mo and W, and the remainder is Ni and unavoidable impurities. and the content of C and N components as unavoidable impurities is C: 0.05% or less, N: 0.04% or less (weight% or more), and has excellent bending workability. Corrosion resistant Ni-Cr alloy. (2) Contains Cr: 38-50%, one or two of Mo and W: 0.1-2%, Cu: 0.1-2%, and the rest consists of Ni and inevitable impurities. Bending workability characterized in that the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0.04% or less (or more by weight) A Ni-Cr alloy with excellent corrosion resistance. (3) Contains Cr: 38-50%, one or two of Mo and W: 0.1-2%, Ca: 0.001-0.01%, and the rest is Ni and unavoidable impurities. Bending characterized in that it has a composition consisting of: and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0.04% or less (or more by weight) A corrosion-resistant Ni-Cr alloy with excellent workability. (4) Cr: 38 to 50%, one or two of Mo and W: 0.1 to 2%, one or more of Zr, Nb, Ta, and Hf: 0.1 to 3%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0.04% or less, A corrosion-resistant Ni-Cr alloy with excellent bending workability. (5) Cr: 38-50%, one or two of Mo and W: 0.1-2%, one or more of Y and rare earth elements: 0.
001 to 0.01%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the corrosion resistance is 0.04% or less (by weight). (G) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Cu: 0.1-2%, Ca: 0.001-0.01%, The remainder consists of Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0.04% or less, (more than 0.05% by weight) ) A corrosion-resistant Ni-Cr alloy with excellent bending workability. (7) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Cu: 0.1-2%, one of Zr, Nb, Ta and Hf or two or more types: 0.1 to 3%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is C: 0.05% or less , N: 0.04% or less (by weight), a corrosion-resistant Ni-Cr alloy with excellent bending workability. (8) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Cu: 0.1-2%, one or two of Y and rare earth elements More than: 0.
001 to 0.01%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the corrosion resistance is 0.04% or less (by weight). (9) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Ca: 0.001-0.01%, Zr, Nb, Ta and Hf One type or two or more types: 0.1 to 3%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is C: 0.059 % or less, N: 0.04% or less, (or more by weight) a corrosion-resistant Ni-Cr alloy with excellent bending workability. (10) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Ca: 0.001-0.01%, one or more of Y and rare earth elements 2 or more types: 0.
001 to 0.01%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the content is 0.04% or more (by weight). (11) Cr: 38-50%, one or two of Mo and W: 0.1-2%, one or more of Zr, Nb, Ta and Hf: 0.1-2% 3%, one or more of Y and rare earth elements: 0.
001 to 0.01%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the corrosion resistance is 0.04% or less (by weight). (12) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Cu: 0.1-2%, Ca: 0.001-0.01%, Zr , one or more of Nb, Ta and Hf: 0.1 to 3%, with the remainder being Ni and unavoidable impurities, and containing C and N components as unavoidable impurities. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the content is: C: 0.05% or less, N: 0.04% or less (by weight). (13) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Cu: 0.1-2%, Ca: 0.001-0.01%, Y and one or more rare earth elements: 0.
001 to 0.01%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the corrosion resistance is 0.04% or less (by weight). (14) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Cu: 0.1-2%, one of Zr, Nb, Ta and Hf or 2 or more types: 0.1 to 3%, 1 type or 2 or more types of Y and rare earth elements: 0.
001 to 0.01%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the corrosion resistance is 0.04% or less (by weight). (15) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Ca: 0.001-0.01%, Zr, Nb, Ta and Hf 1 type or 2 or more types: 0.1 to 3%; 1 type or 2 or more types of Y and rare earth elements: 0.
001 to 0.01%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the corrosion resistance is 0.04% or less (by weight). (16) Cr: 38-50%, one or two of Mo and W: 0.1-2%, Cu: 0.1-2%, Ca: 0.001-0.01%, Zr , Nb, Ta, and Hf: 0.1 to 3%; Y and rare earth elements: 0.1 to 3%;
001 to 0.01%, and the remainder is Ni and unavoidable impurities, and the content of C and N components as unavoidable impurities is: C: 0.05% or less, N: 0. A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized in that the corrosion resistance is 0.04% or less (by weight). (17) In claims 1 to 16, Cr:
A corrosion-resistant Ni-Cr alloy with excellent bending workability characterized by a corrosion resistance of 38 to 47%. (18) In claims 1 to 16, Cr:
A corrosion-resistant Ni-Cr alloy with excellent bending workability, characterized by a corrosion resistance of 43 to 47%. (19) In claims 1 to 16, Cr:
43-47%, C: 0.01% or less, N: 0.01% or less, Corrosion resistance N with excellent bending workability.
i-Cr alloy.