JPS6250433A - Electricity conduction roll alloy for electrical plating - Google Patents

Abstract

PURPOSE:To obtain the titled alloy having superior resistance for corrosion and wear, further good peeling property of plated metal adhered to barrel part surface, by adding prescribed quantities of C, Si, Mn, Cr, Mo to Ni and restricting content of Fe being impurity. CONSTITUTION:The titled alloy is composed of, by weight 0.2-3% C, 0.5-5% Si, <=2% Mn, 20-35% Cr, 2-10% Mo if necessary <=6% W, <=10% Fe being impurity and the balance Ni. The alloy is superior in resistances for corrosion, corrosion wear in corrosive circumstances of plating liquid, in addition thereto has a low platability and a low adhering strength of metal. Consequently, trouble of frequently exchanging roll as usual and polishing cost for roll recovery are markedly decreased and stable, continuous plating operation is maintained, further quality of plated product is improved and stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a current-carrying roll alloy for electroplating that has excellent corrosion resistance, abrasion resistance, etc., and has good peelability of plated metal adhering to the surface of the body.

[Conventional technology]

In addition to the specified current conductivity, the current-carrying roll in electroplating equipment such as continuous electrogalvanizing has corrosion resistance to a plating bath (usually pH 1 to 2), which is a strong acidic liquid, and the ability of the steel plate to be plated to pass continuously through the plating bath. It is necessary to have abrasion resistance that can withstand contact with (threaded plate material).

Further, during use, the energizing roll becomes a cathode like the steel plate to be plated, and the surface of its body is also plated with a plating metal such as zinc, so the adhering plating metal must be removed from the surface of the body.

This is because if a plating operation is performed with the plating metal attached to the surface of the body, the surface of the steel plate to be plated that comes into contact with the body will be scratched, and the quality of the plating will be impaired.

The adhering plating metal is removed by rubbing a grindstone or the like on the surface of the body, so the surface of the body is required to have abrasive wear resistance against sliding contact with the grindstone or the like.

Conventionally, current-carrying rolls for electroplating have been made with a body made of a nickel-based alloy "Hastelloy C" or an alloy such as SUS 316, a high nickel stainless steel.

[Problem to be solved]

However, the above-mentioned conventional current-carrying roll has advantages and disadvantages in terms of corrosion resistance, abrasion resistance, etc., and also has a problem in removing the plated metal adhering to the surface of its body.

In other words, the current-carrying roll whose body is made of the nickel-based alloy "NO1 STEROY C" has no problem with corrosion resistance, but has a low hardness of about 25 to 30 Hs and does not have sufficient wear resistance. Scratches are likely to form on the surface, especially at the contact area of the edge of the plated steel plate.

The flaws are transferred to the surface of the steel plate to be plated, causing deterioration in plating quality. In addition, the surface of the body is extremely susceptible to adhesion of plated metal, and in order to remove it, the surface of the body must be constantly rubbed strongly with a grindstone, etc., so the surface of the body is prone to scratches and wear. easy.

On the other hand, 5t JS 316 stainless steel is used as the body material and t
Le1llll! As for the roll, the hardness is Hs20 ~
It has the same problems as the current-carrying roll made of /'t STEROY C mentioned above, in that it has poor abrasion resistance and the plated metal easily adheres to the surface of the body. Problems also remain in terms of corrosion resistance.

For this reason, in conventional energized rolls, wear and deterioration of the roll body surface progresses rapidly, and polishing is required to repair the body surface in a short period of time, for example, every one month. In addition to being forced to frequently replace the rolls and thereby interrupt operations, they are also forced to bear a large cost burden for re-polishing the rolls.

The present invention aims to provide an improved current-carrying roll alloy for electroplating in order to solve the above-mentioned problems.

[Means and effects for solving the problems] The current-carrying roll alloy for electroplating of the present invention contains C: 0.2 to 3%, Si
: 0.5-5%, Mn: 2% or less, Cr: 20-3
5%, Mo: 2-10%, impurity Fe: 1
0% or less, the remainder substantially consists of Ni, and optionally further contains W: 6% or less.

The current-carrying roll made of the alloy of the present invention has excellent corrosion resistance against plating baths and also has excellent abrasion resistance (hereinafter also referred to as "corrosion abrasion resistance") in the corrosive environment. Moreover, even if plated metal adheres to the surface of the body, the adhesion to the surface of the body is weak, so it can be easily removed with a grindstone, etc., and therefore there is no possibility of scratches or wear and tear on the surface of the body due to the grindstone. Very few.

In addition, since the corrosion resistance, corrosion abrasion resistance, and difficulty in peeling off and removing the plated metal adhering to the surface of the current-carrying roll for electroplating are problems related to the surface, it is necessary to form the entire body of the roll from the alloy of the present invention. There isn't. That is, a cylindrical body serving as the core of the roll body is formed of a different material, and a coating layer (surface layer) made of the alloy of the present invention is formed on the surface thereof by, for example, overlay welding, thereby creating an energized roll. You can also do that. The composition of the alloy of the present invention was determined taking this point into consideration.

The reasons for limiting the components of the alloy of the present invention are as follows.

C: 0.2-3% The presence of C is not preferable from the viewpoint of corrosion resistance, but on the other hand, the presence of Cr
, W, etc. to form carbides, which increases hardness and contributes to improving wear resistance. In the present invention, corrosion resistance is ensured with Cr, W, Mo, etc., and from the viewpoint of wear resistance, at least 0.2% of C is contained. As Cl increases, hardness increases and wear resistance improves; however, when it exceeds 3%, this effect is saturated, and in addition, weldability deteriorates as the material becomes brittle, making it difficult to build up welds. The tendency for cracks to occur increases. Therefore, the upper limit is set at 3%.

Si: 0.5-5% Si is a deoxidizing element, and in the present invention, it is added not only for deoxidizing but also for improving hardness and corrosion resistance.

At least 0.5% is required to achieve this effect. However, if it exceeds 5%, the hardenability will be almost saturated and the tendency of cracking during welding will increase, so the upper limit is set at 5%.

Mn: 2% or less Mn is an element that has deoxidizing and desulfurizing effects, and its amount is 2% or less.
Up to % is sufficient.

Cr: 20-35% Cr greatly improves wear resistance by being dispersed and precipitated in the matrix as chromium carbide.

Further, Cr has a low corrosion dissolution rate in a plating solution, forms a matrix together with Co, Ni, Fe, etc., and forms a dense and strong protective film, thereby providing passivation. At least 20% Cr is required to achieve this effect. The effect increases as the Cr content increases, but if it exceeds 35%, the material becomes brittle and problems arise in weldability, so the upper limit is set at 35%.

Mo=2 to 10% Mo, like Cr, is an element that has a low rate of corrosion and dissolution in a plating solution, and is extremely effective in improving corrosion resistance. This effect starts from 2% and increases as the content increases, but if it exceeds 10%, embrittlement occurs and weldability deteriorates. Therefore, it is set at 2 to 10%.

W: 6% or less W, like the aforementioned Cr and Mo, has the effect of improving corrosion resistance against plating solutions. In addition, like Cr, it forms carbides, which increases the hardness of the metal and contributes to improving wear resistance. However, if the amount added exceeds 6%, the alloy becomes brittle, so the upper limit should be 6%, preferably 0.
It is 5-6%.

Fe: 10% or less Fe is not a necessary component of the alloy of the present invention, but is an impurity element that is allowed to be present in an amount of up to 10%. The reason why 10% is set as the allowable upper limit is that if it exceeds this value, intermetallic compounds such as Fe-Cr will precipitate and corrosion resistance will decrease, and in actual use as a current-carrying roll, the plating metal may not adhere to the body surface. This is because the adhesion becomes strong and it becomes difficult to peel and remove it. If Fe is an impurity and its amount is strictly limited, manufacturing costs will increase due to selection of melted raw materials and removal of Fe in the refining process, but in the alloy of the present invention, Fe is It's not that harmful, 1
Since a relatively large amount of 0% is allowed to be mixed, it is economically advantageous.

Ni: The remaining Ni is a basic component of the alloy of the present invention, which stabilizes the matrix-nox as an austenitic structure and increases its hardness. Further, Ni has a noble ionization tendency, and the corrosive film is dense and stable, so it has excellent passivation ability and provides excellent corrosion resistance against plating solutions.

Furthermore, the important point of the present invention alloy containing Ni as a basic component is that
It has good electrical conductivity as a current-carrying roll, and at the same time,
This means that the surface of the body is poorly plated, and even if plated metal adheres to the surface, the adhesion is weak and it easily peels off. Therefore, it has the advantage that scratches and abrasion on the surface of the roll body caused by grinding with a grindstone or the like for removing attached plated metal can be effectively reduced.

By the way, as shown in FIG. 1, the electroplating current-carrying roll basically consists of a hollow cylindrical body (10) that forms the body of the roll, and shaft members (20) that also serve as power supply members fitted to both ends of the hollow cylindrical body (10). As a member. In addition, (31) is a cooling water flow path, which is defined inside the body by a cylinder (30) fitted concentrically in a hollow hole of the body, and is connected to the shaft member (20).
) is in communication with a flow path (21) bored in the hole.

When the alloy of the present invention is applied as a current-carrying roll material, it is sufficient to form only the surface layer (12) of the body with the alloy of the present invention as shown in the figure, and this is also more economical. In order to form the body (10) having such a multilayer structure, the body core (11) may be made of other suitable materials (for example, SUS).
A cylindrical cast or plastic-worked product made of stainless steel such as 304, carbon steel such as 335C, etc.) is prepared, and a coating layer forming method such as welding overlay or thermal spraying is applied to the outer circumferential surface of the product. The surface layer portion (12) made of the invention alloy may be formed to have an appropriate layer thickness (for example, 1 to 10111). Also,
Alternatively, a sleeve (hollow cylinder) made of the alloy of the present invention
made of the alloy of the present invention by casting or plastic working, etc., and by fitting it into the body core (11) at the bottom of a hole or by other methods to integrate it, or by using a centrifugal casting method. It is also possible to use a method in which a hollow cylindrical body is cast and then another material is cast into the hollow hole to form a two-layered roll body.

〔Example〕

For each alloy having the composition shown in Table 1, a corrosion test, a corrosion 9 wear test, and a weldability test were conducted, and the hardness and plating metal adhesion strength were measured, and the results shown in the right column of the table were obtained.

In the table, incense (floors) 1 to 12 are examples of the present invention, llh 101
-110 are comparative examples. Comparative example 11h101-110
Among them, 1k101 is equivalent to the conventional material SUS 316, Kan 102 is equivalent to the conventional material "Hastelloy C", and 1k103 to 110 have a composition similar to the alloy of the present invention. , is an example in which the content of one of the elements (underlined in the table) deviates from the provisions of the present invention.

Each measurement and test condition is as follows.

(1) Hardness measurement Measure the surface hardness of the sample material using a Shore hardness meter.

[■] Measurement of adhesion strength of plated metal (a) Formation of plated layer After wet polishing (#1000) the surface of the plate-shaped specimen (20m x 30+m) (T), the lead wire ( 2) and connect the surface to be plated (A) (
20m x 2011) was left and masked with resin, and this was used as a cathode, and zinc plating was performed using a zinc plate as an anode.

Plating solution composition: 20g/I! HzSO 1
00g/βN a zS 00150g/j! Z
n S Ot (liquid temperature 50°C), current density: 50A/d
m, distance between electrodes: 30+u (constant), energization time: 50 minutes.

(b) Plating layer peeling test After the above plating, an L-shaped stainless steel plate piece (plate r\
2mm) (P) and hardened for 1 hour at 120"C. Then, in a tensile tester, the L-shaped steel plate piece (P)
) and the support rod (B) that had been previously bonded to the back surface of the test piece (T) were broken by chucking, the peeling status of the plating layer was visually observed, and the breaking load and plating were measured. From the peeling area of the layer, the plating adhesion strength (kg/ca)
seek.

CI) Corrosion Test A test piece (20' x 30 L x 5', w) is immersed in a galvanizing solution, which is a sulfuric acid acidic corrosive solution, for 7 days, and then the corrosion loss (g/mh) of the test piece is measured.

Plating solution composition: 20g/j! H2SO], 00g/m
l! N a 2504.150 g / lZ n S
Oa, liquid temperature #50℃ (1'V) Corrosion wear test A round rod-shaped test piece (15φ x 100L, +u) was rotated at 300 rpm in a galvanizing solution, and a load of 2 kg of 5GP50 was applied to the surface as a mating material. Press with
The weight loss of the specimen due to wear after 7 days of continuous loading is measured. The wear loss of each sample material is compared to 101 (S
It is expressed as a weight ratio, with the abrasion loss of US 316 (equivalent to US 316) being 100.

Plating solution composition: 20g/βH2SO, 100g/IN
azSOa, 150 g/12 ZnSO4 liquid temperature: 50
℃ (V) Weldability test Rod-shaped filler metal consisting of each sample metal (cross section 4 dragons ψ,
(length 200-250cm) by TIG welding method,
Flat base material (SUS304 equivalent material, preheating temperature 600°C
) was overlaid by welding to form an overlay layer with a bead length of 100 mm and a bead width of 20 mm.

After the above-mentioned overlay welding, the base material is
The bead was cut at a total of 5 locations at 1 m intervals in a direction perpendicular to the longitudinal direction of the bead, and the presence or absence of cracks on the cut end face of the built-up layer was determined by liquid penetrant testing.5. Weldability was evaluated. In the table, "○" in the "weldability" column indicates no cracking.
"X" means that there is a crack.

As shown in Table 1, the example of the present invention is made of 5US, which is a conventional material.
316 material (scented 101) and "Hastelloy C" (scented 10)
Compared to 2), it can be seen that the adhesion strength of the plated metal is lower and its releasability is better, and from a comprehensive comparison of hardness and wear loss, it has about three times or more of wear resistance. In addition, as long as the corrosion resistance is equal to or higher than that of the conventional material SUS 316 material, there is no problem as an energized roll, but the corrosion loss of the example of the present invention is that of the SUS 316 material (Fragrance 101).
It can be seen that the corrosion resistance is very small compared to the above, and that the corrosion resistance is sufficient.

In addition, Comparative Example 1 has a composition similar to that of the alloy of the present invention.
Looking at 03 to 110, number 10 lacks Cr content.
3 has low hardness and wear resistance, and conversely, 11h104, which contains excess Cr, has poor weldability and has only a small hardness improvement effect despite its high Cr content. IVh106 has low hardness and lacks abrasion resistance, while IVh106, which contains an excessive amount of C, has poor weldability, and is inferior to the present invention example.Furthermore, IVh107, which lacks M ail 11h108, which contains excessive Mo, has low corrosion resistance, and 11h108, which contains excessive Mo, has problems in weldability, and both 11h109, which contains excessive Si, and 110, which contains excessive W, have poor weldability. It is not as good as the example of the present invention.

〔Effect of the invention〕

The current-carrying roll alloy of the present invention has excellent corrosion resistance and corrosion wear resistance in the corrosive environment of plating solutions, as well as
It has poor adhesion and peelability, and the adhesion strength of plated metal is low.

The current-carrying roll for electroplating having a surface layer made of the alloy of the present invention has a low amount of corrosion due to plating solution and contact with the steel plate to be plated, and is suitable for grinding with a grindstone etc. to remove plated metal adhering to the surface. Since the occurrence of scratches and abrasion due to application is slight, the smooth and beautiful surface condition is maintained for a long period of time. Therefore, the hassle of frequent roll replacement and the cost required for polishing to generate rolls are significantly reduced, stable continuous plating operations are maintained, and the quality of plated products is improved.
A stabilizing effect can be obtained.

The alloy of the present invention is useful as a current-carrying roll alloy for various types of electroplating, such as tin plating, nickel plating, etc., and is not limited to the above-mentioned zinc plating. It is also useful as a material for zinc rolls, etc., which are guide rolls for passing sheets through.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing an example of the layered structure of an energizing roll when the surface layer of the body is formed of the alloy of the present invention, and Fig. 2 CI) and (II) are test pieces related to Examples. It is a perspective explanatory view showing the form of. 10: roll body, 11: body core, 12: body surface layer, T: test piece.

Claims (2)

[Claims] (1) C: 0.2-3%, Si: 0.5-5%, Mn:
A current-carrying roll alloy for electroplating consisting of 2% or less, Cr: 20-35%, Mo: 2-10%, impurity Fe: 10% or less, and the remainder substantially Ni. (2) C: 0.2-3%, Si: 0.5-5%, Mn:
2% or less, Cr: 20-35%, Mo: 2-10%, W
A current-carrying roll alloy for electroplating consisting of: 6% or less, impurity Fe: 10% or less, and the remainder substantially Ni.