JPH0730422B2 - Energizing roll for electroplating - Google Patents

Description

TECHNICAL FIELD The present invention relates to a current-carrying roll for electric plating.

Conventional technology Conventionally, JIS-SCS14 has been used as the energizing roll for electric plating.
However, corrosion-resistant steel such as JIS-SUS316 has been used, but these corrosion-resistant steels are inferior in corrosion resistance such as electric galvanic corrosion and corrosion due to acidic solution, and wear resistance, and the roll surface is significantly roughened. As a result, it required polishing for reuse in a short period of time (eg, one week).

The present applicant has already solved the above-mentioned drawbacks in the conventionally used corrosion resistant steel, does not impair the electrical conductivity as an electric roll for electric plating, and uses an electric zinc plating, an electric tin plating, or an electric alloy plating. Although it has been proposed a current-carrying roll for electric plating, which has excellent corrosion resistance against particularly severe high-current energization conditions, and has high hardness, toughness and strength, and also wear resistance (Japanese Patent Publication No. 58-57501). JP-A-58-207390), and it has been confirmed by industrial implementation that the energizing roll for electric plating according to these inventions can bring desired effects.

Problems to be Solved by the Invention As described above, the previously proposed electric current-carrying roll for electric plating has desired effects, but as a result of industrial implementation, the electric current-carrying roll for electric plating is A new problem has arisen that it is desirable to further improve the corrosion resistance and hardness. The present invention aims to solve this problem,
That is the purpose.

Means for Solving the Problems In order to solve this problem or to achieve the object, the roll according to the present invention has the chemistry as described in "Claims" 1 to 4. It is characterized by being composed of a component range. That is, the roll according to the present invention has a chemical composition of more than 16% Mo and 30% or more in order to improve the hardness as compared with the previously proposed one.
% Or less and Co in the range of 5.8% or more and 35% or less. Furthermore, Nb is used as a main element for stabilizing carbon and improving corrosion resistance, and 1.0% as a composite additive element.
The major difference is that the addition of Ti or less% and the content of Ta, Zr or Hf or less 1.5% is added.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the accompanying drawings showing examples thereof and test procedures.

First, as described above, in the roll according to the present invention, Ni contained Cr, Mo, Co, Cu and Nb as main components, or Cr, Mo, Co, W, Cu and Nb as main components. However, as described in detail later, in order to have both corrosion resistance and wear resistance, solid solution strengthening of Co in the austenite base and Ni, M in the austenite base are included.
The greatest feature is that a high hardness intermetallic compound containing o, Cr and Co as main components is uniformly dispersed to form a roll.

Therefore, first, the reason why each chemical component in the roll of the present invention is limited to the above specific range will be described.

Ni stabilizes the matrix as an austenite structure as a basic component, and further forms an intermetallic compound having high hardness with Mo as the amount of Mo increases, and contributes to increase in hardness. In addition, Ni itself is noble due to the ionization tendency of the metal, so the corrosion dissolution rate is low, and since the corrosion-produced film is dense, it has a large protective action and an excellent passivation ability.

When Mo is added to Ni, it is solid-solution strengthened as the content of Ni increases, and at the same time, the volume% of high hardness intermetallic compound is increased.
However, the toughness is unavoidably decreased, but the hardness is increased, and further, the increase in Co has a complex effect on the hardness and wear resistance is improved. On the other hand, the corrosion resistance can be prevented to a minimum by solution treatment. This hardness increasing tendency is proportional to the amount of Mo, and the effect appears at 16 wt%, but if it exceeds 30 wt%, the corrosion resistance deteriorates and embrittlement occurs.

Cr forms a matrix with Ni, Mo and Co that have a low corrosion dissolution rate and also have a passivation ability, form a stronger protective film, and give a passivation ability. In the present alloy, the effect of Cr is remarkable at 14 wt%, but when it exceeds 21 wt%, it becomes saturated, which causes brittleness due to the formation of a weak intermetallic compound, and also deteriorates the corrosion resistance. Let

Co causes a solid solution strengthening action by forming a solid solution in the austenite matrix, increasing the matrix hardness and at the same time, in the intermetallic compound.
It replaces Ni and changes the morphology of intermetallic compounds. The hardness of the matrix increases due to the combined effect of increasing the Mo content in addition to increasing the Co content. Mo content is 22%
When changing to Co 0,15 and 30%, the hardness becomes HRC23 (HRB100), HRC30 (HRB105.5) and HRC37.5, respectively.
Hardens with (HRB108) and hardness increases when Co content increases by 15%
HRC7 ~ 7.5 (HRB2.5 ~ 3.5) rise. In this alloy, if the content of Co is less than 5.8%, the Mo content increases, so there is no effect, and if it exceeds 35%, embrittlement occurs and the cost also increases. limit.

Cu constitutes a matrix formed by the coexistence of Ni, Mo and Co, forms a strong protective film on the surface layer, and imparts a passivation ability. However, the Cu content is effective even if added in a small amount of 0.1 wt%, but if it exceeds 5 wt%,
Since it causes embrittlement and has no effect on improving the corrosion resistance, the content of this alloy is limited to 0.1 wt% or more and 5 wt% or less.

Although C is unavoidable in production, it is preferable that the content of C be as small as possible. That is, since the content of C causes the precipitation of carbides due to its inclusion and the deterioration of corrosion resistance due to this carbide, 0.06 wt% or less is preferable, but 0.1 w
Even if it is less than t%, it can be practically made impossible by completely performing the solution treatment.

Nb has the effect of stabilizing excess carbides and also has the effect of enhancing the passivation ability. To obtain this effect, Nb ≧ 10 × C wt% is necessary, so in this alloy, it is limited to 1.5 wt% or less.

In addition, in order to stabilize this excess carbide, Ti, T together with Nb
Composite addition of elements such as a, Zr and Hf is also effective. To obtain this effect, Ti ≧ 5 × C wt%, Ta ≧ 15 × C wt%,
Zr ≧ 10 × C wt% and Hf ≧ 15 × C wt% are necessary. Therefore, in this alloy, Ti is 1.0 wt% or less, Ta, Zr and Hf
Are limited to 1.5 wt% or less, respectively. However, for claims 1 and 2, 1/10 (% Nb)
The formula ≧ (% C) is defined as 1/10 (% Nb) +1/5 (% Ti) +1/15 (% Ta) for the claims 3 and 4
The expressions +1/10 (% Zr) +1/15 (% Hf) ≧ (% C) are satisfied.

Regarding W, like Mo, the corrosion resistance is improved and the strength is improved, but if it exceeds 3 wt%, in order to form a uniform solid solution, a solution treatment of 1,220 ° C or higher is required.
In this alloy, it is limited to 3 wt% or less.

The Si content varies depending on the manufacturing method, but it is necessary to contain Si in an amount of 2.0 wt% or less in terms of deoxidation, hot water flow and the like. Moreover, when the amount of Si increases, precipitation of intermetallic compounds is promoted,
Although hardness increases, corrosion resistance decreases, so it is limited to 2.0 wt% or less.

Note that, instead of Si, it is also effective to use Al or the like as a deoxidizing element as much as possible in production.

Mn widens the region of the γ phase, stabilizes it, and improves hot workability, but its effective content is 1.5 wt% or less.

Next, an example of the energizing roll for electric plating according to the present invention will be described based on the results of experiments conducted in comparison with a conventional all material.

Table 1 shows the chemical composition (% by weight) of the test material, and Table 2 shows
It shows the relationship between current-carrying electrical corrosion resistance / wear resistance and hardness. In addition, as shown in the attached drawing, this electric resistance to electrical corrosion and abrasion resistance was tested in solution 1 under the conditions of 30% ZnSO ₄ + 3% H ₂ SO ₄ , PH1.2, and current density of 40 A / dm ^2. The roll 2 was dipped, the brake roll 3 and the drive roll 4 were arranged before and after this, and a constant tension was applied through the mild steel strip 5 to carry out the test. In addition, this corrosion and wear resistance test
The roll life ratio (see Note 2 in Table 2) and the rate of scratches such as scratches and push scratches that occurred on the roll surface due to mechanical factors after 1 week of energization (see Note 3 in Table 2) I compared them.

As shown in Table 1, the test materials are JIS conventional alloys.
-SOS 14 and SUS 316, and the invention "Electrical current-carrying roll" according to the above-mentioned applicant's earlier patent application (JP-A-58-58).
No. 7, 10, 11, 14, 16, and 17 alloys described as examples of the invention alloy in the specification of Japanese Patent No. 207390). Examples of the alloys of the present invention are Nos. 7, 8 and 9 in which the Co content of the basic component is changed within the limited range of the present alloy.
And In addition, Nos. 10, 11 and 12 were prepared by changing the amount of Mo as the basic component and adding W. In order to stabilize the excess carbide in the No. 8 component (Co median value), Ti was added to Nb, Ta, Ti and Zr and
No.13,14,15 and 1 with Hf compound added respectively
It was set to 6. For No.17 to 20, W is added to No.8 component,
Ti, Ta, Ti and Zr and Hf are added respectively.

Regarding the corrosion amount in Table 2, the test piece was immersed in a boiling sulfuric acid solution having a concentration of 50%, and the erosion degree g / cm ² / day was obtained.

As can be seen from Table 2, the alloy of the present invention (solution treatment temperature 1,
170 ℃) is JIS-SCS14, SUS316 and No.1,2,3,4,5 and 6
The alloy has better corrosion resistance and higher wear resistance than the alloy No. 1, so it is possible to prevent scratches and push scratches on the roll surface due to mechanical factors, and less wear due to mild steel strip. Roughness of the roll surface is unlikely to occur, and the corrosion and wear resistance properties required for the current-carrying roll are relatively obtained. As is clear from Table 2, the roll according to the present invention has a life ratio of 25 to 42 in terms of corrosion resistance and wear resistance as compared with the conventional roll using JIS-SUS316.
The scratch occurrence rate is between 13 and 20%. This is because the matrix hardness is improved by increasing the Co content and Mo forms a high hardness intermetallic compound in the matrix. This is considered to be because the hardness of the whole is increased by doing so, and scratches and pressing scratches do not occur on the roll surface.

Furthermore, the electrical conductivity is the same as that of JIS-SOS14 and SUS316.
Although it is inferior to 128 to 141 μΩ-cm with respect to μΩ-cm, it is said that in practice up to 170 μΩ-cm can be used, so this point is not a problem.

Next, considering Table 2, between Nos. 7, 8 and 9 in which the Co content of the basic component is changed, No. 9, which is the upper limit of Co, is slightly inferior in corrosion resistance. Due to the high hardness, the life ratio is 40 times that of JIS-SUS316, and the scratch occurrence rate is 15 times.

In addition, N containing W added to each of No. 7, 8 and 9
The life ratio of o.10, 11 and 12 is 27 to 42 compared to JIS-SUS316.
It shows double the value, the rate of scratch occurrence is 14 to 18 times, the corrosion resistance is also improved compared to Nos. 7, 8 and 9, and the hardness is slightly improved. The effect of addition of is recognized.

Next, in order to stabilize the excess carbide in the No. 8 component with the median Co content, Nb was added with Ti, Ta, Ti and Zr and Hf respectively, and the life of No. 13, 14, 15 and 16 was added respectively. The ratio is 32 to 34 times that of JIS-SUS316, and the scratch occurrence rate is 17 to
It shows 18 times the value, which is almost the same as No. 8 which is the basic component.

Nos. 17, 18, 19 and 20 were added with W, and in order to stabilize excess carbides in No. 11 with a median Co content, Ti, Ta, Ti were added to Nb.
And Zr and Hf are respectively added in combination.
The life ratio of No. 17, 18, 19 and 20 is 35 to JIS-SUS 316.
The value is 37 times, and the scratch occurrence rate is also 15 to 16 times, which is almost the same as No. 11.

As described above, the basic component of the roll according to the present invention is Ni-
Although it is a Cr-Mo-Co-Cu-Nb-based roll, the roll according to the present invention has a comprehensive corrosion resistance even under severe corrosion conditions during electrical galvanic corrosion and even severe wear conditions. It has abrasion resistance, which is higher in hardness and superior to that obtained by the patent application by the present applicant. Therefore, the current-carrying roll according to the present invention,
JIS-SCS14 and SUS316 can also be used under the current corrosion resistance condition PH 0.6 to 1.6 that could not be obtained, and especially when wear is a problem, it is effective and has excellent corrosion resistance. It exhibits wear resistance, and it can be used for practical purposes without any problem in terms of electrical conductivity.

As described above, the present invention provides a more appropriate energizing roll for electric plating, which requires these properties, as compared with the one previously proposed as a patent application.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the procedure of a current-carrying electrical corrosion resistance / wear resistance test method. 1 ... Solution; 2 ... Test roll; 3 ... Brake roll; 4 ...
… Drive roll; 5 …… Mild steel strip.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yoshio Hara 5-25-12 Sagamigaoka, Zama City, Kanagawa Prefecture (72) Inventor Kenji Inada 1 Kimitsu, Kimitsu City, Chiba Shin Nippon Steel Co., Ltd. Inside the Kimitsu Works (56) References JP-A-58-207390 (JP, A)

Claims (4)

[Claims] 1. By weight%, C 0.10% or less Si 2.0% or less Mn 1.5% or less Cr 14% or more 21% or less Mo 16% or more and 30% or less Cu 0.1% or more 5.0% or less Nb 1.5% or less Co 5.8% or more Includes 35% or less (however, 1/10 (% Nb) ≧ (% C)), the balance being unavoidable impurities and consisting essentially of Ni, and hardness HRB97-108
The current-carrying roll for electroplating is characterized by 2. By weight% C 0.10% or less Si 2.0% or less Mn 1.5% or less Cr 14% or more 21% or less Mo 16% or more 30% or less Cu 0.1% or more 5.0% or less Nb 1.5% or less W 3.0% or less Co contains 5.8% or more and 35% or less (however, 1/10 (% Nb) ≧ (% C)), the balance is inevitable impurities and substantially Ni, and hardness HRB97-108
The current-carrying roll for electroplating is characterized by 3. By weight%, C 0.10% or less Si 2.0% or less Mn 1.5% or less Cr 14% or more 21% or less Mo 16% or more and 30% or less Cu 0.1% or more 5.0% or less Nb 1.5% or less Co 5.8% or more Including 35% or less, Ti 1.0% or less, Ta 1.5% or less, Zr 1.
5% or less, Hf 1.5% or less, including one or more components (however, 1/10 (% Nb) + 1/5 (% Ti) + 1/15
(% Ta) +1/10 (% Zr) +1/15 (% Hf) ≧ (% C)),
The balance consists essentially of Ni with unavoidable impurities, and hardness
HRB97-108 is a current-carrying roll for electroplating. 4. By weight%, C 0.10% or less Si 2.0% or less Mn 1.5% or less Cr 1% or more 21% or less Mo 16% or more and 30% or less Cu 0.1% or more 5.0% or less Nb 1.5% or less W 3.0% or less Co 5.8% to 35% inclusive, Ti 1.0% or less, Ta 1.5% or less, Zr 1.
5% or less, Hf 1.5% or less, including one or more components (however, 1/10 (% Nb) + 1/5 (% Ti) + 1/15
(% Ta) +1/10 (% Zr) +1/15 (% Hf) ≧ (% C)),
The balance consists of unavoidable impurities and Ni, and has a hardness of HR.
B97-108 is a current-carrying roll for electroplating.