JPS6199652A - Electrically conductive roll - Google Patents

Abstract

PURPOSE:To obtain an electrically conductive roll having superior corrosion and wear resistances by forming a work-hardened layer having a specified Shore hardness or above on the surface of the body of a roll made of an Ni alloy having a specified composition. CONSTITUTION:The body of a roll is made of an Ni alloy having a composition consisting of, by weight, <0.15% C, <2% Si, <2% Mn, 15-30% Cr, 4-10% Mo, 0.2-2% Al, <10% Fe and the balance Ni with inevitable impurities. The composition may further contain one or more among 0.1-3% Nb, 0.05-1% Ti, 0.01-0.5% V and 0.001-0.1% B. A work-hardened layer having >=40 Shore hardness (Hs) is formed on the surface of the body.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a current-carrying roll used in electroplating equipment and the like.

[Problems with conventional technology]

In addition to the required electrical conductivity, the current-carrying roll used in electroplating equipment, such as continuous electrogalvanizing, has corrosion resistance against a plating bath consisting of an acidic solution, and the strength of the steel plate to be plated (passing material) that passes continuously through the plating bath. It must have abrasion resistance to withstand contact.

Basically, as shown in Fig. 4, the current-carrying roll has roll ends (2
, 2) are fitted and welded together, and the plate (71) contacts the peripheral surface of the roll body.

Traditionally, 5O3-14 and S
Nickel-containing stainless steel alloys such as US-316 have been used exclusively, and energized rolls have been used in which the roll body is a sleeve made of a cast or forged solution heat-treated material of these alloys.

However, recently, the performance of surface-treated steel sheets, especially their corrosion resistance, has improved.
The environment in which energized rolls are used is becoming significantly harsher due to demands for quality such as deep drawing formability, as well as higher production line speeds, higher current flow rates, and lower pH of plating bath solutions. Conventional energized rolls cannot withstand such harsh usage environments,
Corrosion under energized conditions, abrasion due to contact with the plate-carrying material, and roughness due to scratches due to plating scum are likely to occur.

As a result, the useful life of the roll body is significantly shortened due to rough skin, and as a result, the frequency of roll replacement increases, forcing the plating line to suspend operation each time.
A huge amount of cost is required for re-polishing the rolls in order to reuse them.

[Problem of invention]

In order to cope with the harsher usage conditions of the above-mentioned energized rolls, improve electroplating operation efficiency, reduce maintenance costs, and improve plating quality, we have developed a system that improves the corrosion and abrasion resistance of the body surface, especially in corrosive liquids. The purpose of this invention is to provide a current-carrying roll with excellent abrasion resistance (corrosion abrasion resistance).

[Technical means and effects]

The present invention uses a nickel-based alloy with a specific chemical composition and excellent corrosion resistance as the material for the roll body, and by work-hardening the surface of the roll body, the wear resistance, especially the corrosion and wear resistance, is dramatically improved. It is elevated.

In the first energized roll according to the present invention, the roll body has C:
0.15% or less, Si: 2.0% or less, Mn: 2.0%
Below, Cr: 15.0-30.0%, Mo: 4.0
~LO60%, A1: 0.2-2.0%, Fe
: 10.0% or less, the remainder is made of a nickel-based alloy consisting essentially of Nt, and the surface has Shore hardness (Hs
) The second energized roll according to the present invention is characterized in that 40 or more work-hardened layers are formed, and the roll body contains Nb:0. 1-3.
0%, Ti: 0.05~1.0%, V: 0.01~
0.5%, B: Any 1 from 0.001 to 0.1%
Contains a species or two or more elements, the remainder being substantially Ni
It is characterized in that it is made of a nickel-based alloy, and a work-hardened layer with a Shore hardness ()(s) of 40 or more is formed on its surface.

The nickel base metal forming the body of the current-carrying roll of the present invention is
The current-carrying roll contains Al, and the second
In the current-carrying roll, AIl, N b −, T
The most characteristic feature is that it contains i, ■, B, etc. in combination. Regarding the current-carrying roll of the present invention, the reasons for limiting the composition of the alloy forming the body will first be explained.

c: o, is% or less C content (2) is more advantageous as it is less from the viewpoint of corrosion resistance. 0.15% in order not to impair the corrosion resistance as a current-carrying roll.
is the upper limit. Preferably, it is less than o,io%. Note that C generally has the effect of increasing wear resistance, but
For use conditions such as an energized roll where corrosion and abrasion act synergistically under energized conditions rather than simple abrasion, the inclusion of C is not particularly required, and therefore no lower limit is specified.

Si: 2.0% or less Si is added in an appropriate amount for deoxidation during alloy melting and to improve castability such as flowability during casting.
l need not exceed 2.0%.

Mn: 2.0% or less Similar to Si, Mn is added in an appropriate amount for deoxidizing the molten alloy, improving castability, etc. The amount need not exceed 2.0%.

Cr: 15.0 to 30.0% Cr acts to increase hardness by precipitation of intermetallic compounds with Ni, Mo, and Af. It also forms a strong passivation film and is effective in improving corrosion resistance.

To obtain these effects, it is necessary to contain at least 15.0%, but if excessively added, the toughness of the material decreases, so the upper limit should be 30.0%. A more preferable content is 15.0 to 25.0%.

Mo: 4.0 to 10.0% Mo is extremely effective in improving acid resistance, especially corrosion resistance to non-oxidizing acid solutions such as sulfuric acid and hydrochloric acid (electroplating baths are solutions of this type). play. It also has the effect of improving hardness and wear resistance. At least 4.0% content is required to exhibit these effects, but 10.0%
If the content exceeds 10.0%, the improvement in effectiveness will be small despite the increase in Mo content, and the economic disadvantage of using a large amount of expensive Mo will increase, and the toughness will decrease, so 10.0% is the upper limit. do.

More preferably, it is 6.0 to 10.0%.

Fe: 10.0% or less Fe has the effect of increasing hardness. Containment 1 is io, o%
Up to this point, there is no particular adverse effect on corrosion resistance.

From an economic point of view, it is advantageous to reduce the amount of expensive N1 and increase the fee, but from the point of view of corrosion resistance, it is advantageous to reduce the amount of expensive N1 and increase the fee.
The upper limit is %. Preferably it is 4.0 to 10.0%.

Al: 0.2-2.0% Aj! is an element that is usually added up to about 0.1% as a deoxidizing agent, but in the alloy of the present invention, 7/l is an extremely effective element that satisfies both corrosion resistance and corrosion wear resistance in the energized state. Based on the knowledge that there is, in order to obtain this moving bed, the lower limit is set to 0.2%. In addition, in order to obtain the wedge addition effect when Nb, Ti, ■, B, etc. described below are contained in a composite manner, 0.2% or more is required. However, if it is contained in an excessive amount, precipitation of intermetallic compounds with Ni becomes noticeable, which tends to reduce the toughness and weldability of the material.
The upper limit is 2.0%. More preferable content is 0.5~
It is 1.5%.

Nb: 0.1-3.0% Nb is effective in improving corrosion resistance and abrasion resistance, especially corrosion and abrasion resistance, in combination with Al. At least 0.1% is required to obtain this effect, but if too much is added, the quality of the alloy will deteriorate, and its suitability as a structural material for 1JT1 electric rolls will be impaired due to deterioration of toughness, weldability, etc. . Therefore, the upper limit is set at 3.0%. A more preferable content is 0.5 to 2.0%.

Ti: 0.05 to 1.0% Like Nb, Ti, in coexistence with Al, has the effect of greatly improving corrosion resistance and abrasion resistance, especially corrosion and abrasion resistance. To obtain this effect, the content must be at least 0.05%, but if added in large amounts, quality, toughness, and weldability will deteriorate, so the upper limit is set at 1.0%. More preferably, it is 0.08 to 0.7%.

V: 0.01 to 0.5% (2), in coexistence with Al, greatly contributes to improving corrosion resistance and abrasion resistance, especially corrosion and abrasion resistance. To achieve this effect, at least 0.01% is required.

The effect increases as the content increases, but when it exceeds 0.5%, the effect is almost saturated. Therefore, the upper limit is set at 0.5%. A more preferable content is 0.05 to 0.3%.

B: 0.001-0.1% B, in coexistence with A', greatly contributes to improving corrosion resistance and abrasion resistance, particularly corrosion and abrasion resistance.

At least 0.001% is required to achieve this effect. Even if added in a large amount, there is no problem with wear resistance etc., but weldability deteriorates, so the upper limit should be 0.1%. A more preferable content is 0.005 to +1.08%.

Note that the remaining Ni may contain 265% or less of CO.

The body of the energizing roll of the present invention is made of the above alloy, and has a hardened layer formed on its surface by cold working. The surface hardness is desirably at least Shore hardness (Hs) = 1O from the viewpoint of ensuring corrosion and wear resistance in actual use.

Cold working to introduce a work hardening layer into the roll body is
For example, as shown in FIG. 3, a roll (101) is chucked (30, 30) L on a lathe, and while the roll is rotated around the axis at an appropriate rotation speed, the surface of the body is
This is achieved by pressing a processing jig such as a roller (20) with an appropriate pressing force instead of the hide for lathe processing, and gradually shifting the roll in the axial direction. For pressing, in addition to rollers, a tool such as a bearing or a cutting tool without a cutting edge can be used as a processing jig.

The surface hardness introduced by cold working can be easily increased to 3[ffi] depending on the working conditions in the cold working. The above pressing is done at a pressure of 50kg during processing.
By processing the pressing at f/n” or more, Hs40
It is possible to provide a surface hardness of more than 100%.

Figure 1 shows the pressing pressure (kg (/as)) and the resulting surface hardness (Hs) when the outer surface of a centrifugal force casting sleeve (outer diameter: 300 mm) is processed by a roller. The following is an example of the relationship between the following: The test metals are (1) and (If) below, and in the figure, (i) is the sleeve of alloy ■ (hereinafter referred to as sleeve ■), and (11) is the sleeve of alloy ■ ( The hardness of sleeve (2) is shown below.The surface hardness before cold working is Hs27 for sleeve (1) and Hs29 for sleeve (II).

"& [C: 0.02%, Si: 0.78%, Mn: 0.
95%, Cr: 21.05%, Mo: 8.1%, A
j! : 0.95%, Fe: 4.8%, balance Nt.

Alloy II C: 0.03%, Si: 0.90
%, Mn: 0.76%, Cr: 20.7%, Mo near, 7%, Aj! :1.02%, Nb:0.42%, T
i: 0.36%, Fe: 4.5%, V: 0.
21%, 13: 0.035%, balance Ni.

As shown in Fig. 1, in the pressing process, the desired surface hardness can be imparted by adjusting the pressure, and for the sleeve (1), the pressing pressure is 50 kgf/m.
*2, and sleeve (II) Te4;! Pressure is 4
3kgf/u2, and each has a surface hardness of Hs40 or higher.

FIG. 2 shows the above-mentioned sleeve (1) and sleeve (II).
), an example of the hardness distribution in the wall thickness direction after cold working is shown. In the figure, (1) shows the hardness distribution of the sleeve (1), and (ii) shows the hardness distribution of the sleeve (II). However, the surface hardness is Hs51 for sleeve (1) and Hs55 for sleeve (II), which is Figure 0. If the surface hardness is sufficiently increased by cold working, work hardening can be achieved deep down.
Sleeve (1) has a Vickers hardness (up to a depth of about 1 ms), and sleeve (II) has a Vickers hardness (up to a depth of about 1 ms).
HV) High hardness of 260 or higher.

In actual use of an energized roll, the surface hardness of the threading material that comes into contact with the roll body is usually HV150 to 200, and is about HV250 at most. If you give it a high hardness, it will still hold up even if it is reprocessed 2 to 3 times after use (the grinding allowance per time is usually about 0.2 to 0.3 mm/diameter). The surface hardness of the body is higher than that of the threaded material, so
Good wear resistance is maintained over a long period of time. If the reprocessing process is repeated and the remaining amount of the initially formed work-hardened layer becomes insufficient, cold working may be performed again during the reprocessing process to work harden the layer again.

In addition to the above-mentioned method, the cold working for forming the work-hardened layer may include drawing processing (preferably with an area reduction rate of 5% or more).
Alternatively, it can also be performed by hammering such as peening, shot blasting, or the like.

To explain a specific example of the manufacturing process of the current-carrying roll of the present invention, first, a hollow cylindrical sleeve is manufactured by centrifugal casting, subjected to solution heat treatment, and then its inner and outer diameters are machined (cut) to required dimensions. A mandrel is interposed therebetween and the sleeve is set on a lathe, and the outer surface of the sleeve is pressed to form a desired hardened layer as shown in FIG. Next, the parts at both ends of the sleeve into which the roll ends are fitted are lathed to the required dimensions, and in some cases only the inner diameter is polled. Thereafter, separately prepared roll ends are fitted onto both ends of the sleeve, welded and joined, and the sleeve surface is then polished to complete the intended energizing roll. Cold working the outer surface of the sleeve may be performed after the sleeve has been assembled with the roll end. Therefore, this cold working can be carried out as appropriate even when repolishing the roll.

In general, when cold working is performed, there is a concern that corrosion resistance may decrease, but there is no need to worry about this in practice, as long as the application is limited to current-carrying rolls such as electroplating. Furthermore, it has been confirmed that there is no problem with electrical conductivity.

〔Example〕

Example 1 Specimens made of each alloy shown in Table 1 were subjected to predetermined treatments to prepare test pieces, and each was subjected to a corrosion wear test, with the results shown in Table 2 being obtained. The preparation conditions and test conditions for the test piece are as follows.

(1) Preparation of test piece (1) Flavoring 1 (Sample metal: Al) Solution heat treatment of centrifugal casting material (1150°C x 2Hr)
-Water cooling), a cylindrical test piece (15 gmφ) is taken, and its surface is subjected to cold pressing with a roll (pressing is done with a pressure crab of 50 to 120 kgf/am2) to harden the surface.

(2) Incense 2 (Prepared gold: B1 (SC3ld equivalent material))
Solution heat treatment of centrifugal casting material (1150”c x
After cooling for 2 hours (water cooling), a cylindrical test piece (15 mm) was collected.

(3) Adding incense 3 (Prepared gold CI (material equivalent to Hastelloy C)
Solution heat treatment of centrifugal casting material (1150℃×2Hr)
-Water cooling), then a cylindrical test piece (15 φ) is taken.

(4) Incense adding 4 (sample metal: Al (invention alloy)) test Kl
A cylindrical test piece (15 m-
φ) is collected.

(n) Corrosion abrasion test specimen (15 mm φ x 100 mm 1) was kept at room temperature in a plating bath solution (composition: ZnSO440Q g/l, Zn
CEz 30g/(1, pH 1,5), 360 r
While rotating at pm, a 5GP50A mating material was pressed against this with a load of 5 kgf /caz, and the wear after 2 days? Measure the amount of li (g/m).

Samples made of each alloy shown in Table 3 were subjected to a prescribed heat treatment to prepare test pieces, and each was subjected to a corrosion wear test, with the results shown in Table 1 being obtained. The test piece preparation conditions and test conditions are as follows.

(1) Preparation of test piece + 1) Flavoring l (Sample metal: A2) Solution heat treatment of centrifugal casting material (1150°C x 2Hr)
-Water cooling), a cylindrical test piece (15 dragons φ) was collected,
The surface is subjected to cold pressing using a roll (pressing is performed at a pressure of 50 to 120 kirf/la'') to harden the surface.

(2) Incense 2 to 4 Same as that of the perfume with the same number in Example 1.

(n) Corrosion wear test Same as Example 1.

As shown in each example, the examples of the present invention all have high surface hardness and excellent abrasion resistance in a strongly acidic plating bath solution. On the other hand, in Comparative Example No. 002 using a conventional material equivalent to 5O3-14, significant wear occurred in the plating bath solution.

In addition, Comparative Example No. 3 using a material equivalent to Hastelloy C, which is a conventional material, is compared to Comparative Example No. 12 using a material equivalent to 5O3-14.
Although the wear resistance is better than that of the example of the present invention, it is far inferior to that of the example of the present invention. In addition, comparative example No.

As shown in No. 4, even if the alloy specified by the present invention is used as a material, the corrosion wear resistance is not as good as that of the examples of the present invention when the specified surface hardening is not performed by cold hardening.

〔Effect of the invention〕

The energized roll of the present invention has excellent wear resistance in a corrosive environment compared to conventional rolls due to the synergistic effect of the material properties of the rope material and cold work hardening. A good surface condition is maintained. Therefore, the hassle of frequent roll replacement and the cost required for roll regrinding are significantly reduced, stable and smooth plating operations are maintained, and the resulting plating quality is improved and stabilized. brought about. Of course, electroplating is not limited to zinc plating, but can also be applied to tin plating, nickel plating, etc. as a current-carrying roll for various electroplating. It can also be used as a current-carrying roll in degreasing equipment, etc., offering improved stability and durability over conventional materials.

[Brief explanation of drawings]

Figure 1 is a graph showing the relationship between cold pressing pressure and surface hardness of the energized roll body, Figure 2 is a hardness distribution diagram in the thickness direction of the energized roll body, and Figure 3 (CI) is a graph showing the relationship between cold pressing pressure and surface hardness of the energized roll body. FIG. 4 is a front view showing a specific example of the cold working method of the part, FIG. 4(n) is a side view, and FIG. 1: roll body, 2: roll end, 10: energized roll, 20: cold working jig.

Claims (2)

[Claims] (1) The roll body has C: 0.15% or less, Si: 2.
0% or less, Mn: 2.0% or less, Cr: 15.0 to 30
．． 0%, Mo: 4.0-10.0%, Al: 0.2-2
．． 0%, Fe: 10.0% or less, and the remainder is essentially Ni, and is characterized by having a work-hardened layer with a Shore hardness (Hs) of 40 or more formed on the surface. An energized roll with excellent corrosion and wear resistance. (2) The roll body has C: 0.15% or less and Si: 2.
0% or less, Mn: 2.0% or less, Cr: 15.0 to 30
．． 0%, Mo: 4.0-10.0%, Al: 0.2-2
．． 0%, Fe: 10.0% or less, and Nb: 0.1~
3.0%, Ti: 0.05-1.0%, V: 0.01-
0.5%, B: 0.001-0.1% 1 or 2
The alloy is made of a nickel-based alloy containing at least 50% of Ni, with the remainder being essentially Ni, and has excellent corrosion and wear resistance, characterized by a work-hardened layer with a Shore hardness (Hs) of 40 or more formed on its surface. energized roll.