JPS61279546A - Copper or copper alloy clad steel plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Fields] The present invention is applicable to ship hulls, seawater desalination equipment, heat exchanger tube sheets, etc., steel or copper alloy clad steel sheets, and chemical plants in general. Concerning copper or copper alloy clad steel sheets.

[Conventional technology]

Conventionally, copper or copper alloy clad steel sheets used for hull shells, seawater desalination equipment, heat exchanger tube sheets, etc. have been produced by rolling or overlaying on a base carbon steel sheet 01, as shown in Figure 3. Alternatively, clad steel has been used in which copper or copper alloy 02 (for example, 9/1 Cypronickel, etc.) having a wall thickness of about 2 to 5 mm is bonded to one or both sides of the carbon steel plate by diffusion bonding or the like. .

[Problem that the invention seeks to solve]

However, conventional steel or steel alloy clad steel plates do not have sufficient corrosion resistance against high-temperature main groove water, brine, contaminated seawater, and various chemicals, and localized corrosion such as pitting corrosion may occur in the steel or steel alloy. . When such local corrosion progresses and penetrates the steel or steel alloy, the carbon steel plate side rapidly corrodes, leading to leakage accidents.

Figure 4 shows the corrosion that occurs in conventional copper or copper alloy clad steel plates.

In Figure 4, pitting corrosion occurred in copper or steel alloy 02.
3 gradually progresses and reaches the boundary between copper or copper alloy 02 and base material carbon steel 01. In such a state, due to the difference in natural electrode potential between copper or steel alloy 02 and the base material carbon steel 01, corrosion 04 (so-called electrolytic corrosion) on the base material carbon steel 01 side rapidly progresses, and in a short time carbon steel 011 penetrate through.

The present invention aims to provide a steel or copper alloy clad steel plate that can overcome the above-mentioned leather alloys that occur in conventional copper or copper alloy clad steel plates.

[Means for solving problems]

In order to solve these problems that occur in conventional copper or steel alloy clad steel sheets, the present invention aims to solve these problems by making the natural electrode potential between the copper or copper alloy composite material and the base material carbon steel more noble than that of the plated copper or copper alloy. And, it is an all-metallic material with excellent corrosion resistance.

That is, the present invention provides a steel or copper alloy material in which all metals having a natural electrode potential higher than that of plated copper or steel alloy and having excellent corrosion resistance are interposed between the steel or copper alloy composite material and the base steel. It is a copper alloy clad steel plate.

[By interposing a metal whose working natural electrode potential is higher than that of copper or copper alloy between plated copper or copper alloy and carbon steel,
Even if local corrosion occurs in plated copper or copper alloy and progresses, the progress of corrosion in the plate thickness direction can be prevented by electrochemical action between the metal and the copper or copper alloy. .

[Example FIG. 1 shows an embodiment of the present invention.

In Fig. 1, the steel alloy clad steel plates are a carbon steel plate 11 with a plate thickness of 12mm and a 9/1 Cypronickel plate 1 with a plate thickness of 2mm.
A 15-t thin plate of Hastelloy C having a thickness of α5cm was placed between the two and joined together by hot rolling. Ninth, to facilitate the bonding between these materials, 9/1 Cyprus nickel plate 12/Hastelloy C thin plate 13 and Hastelloy C thin plate 1
5/ A thin nickel plate 14 having a thickness of α05− is inserted between each of the carbon steels 11.

In the present invention, as the steel alloy, in addition to 9/1 Cypronickel, 7/3 Cypronickel, naval brass, bronze, aluminum bronze, etc. can be used. In addition to Hastelloy ○, Inconel 6 is also used as a metal for the intermediate layer.
00. In; Nell 625. N1 such as Inconel 825
Base metal, Ti, Zr, etc. can be used.

〔Effect of the invention〕

As shown in FIG. 1, artificial defects of α5■φ than that of Hastelloy 013 were added to the 9/1 Cypronickel clad steel plate 971 Cypronickel 12 according to the present invention.
The specimens were immersed in main groove water at a temperature of 1rLe, and a corrosion test was conducted over a period of approximately 3 months.

FIG. 2 shows a cross-sectional view illustrating the state of corrosion that occurred in the 9/1 Cypron clad steel.

In Fig. 2, corrosion progresses in the artificial defect 15 made on the 9/1 Cypronickel, forming a large cavity 16.Then, the corrosion stops at the Hastelloy C thin plate 13, and the corrosion progresses in the thickness direction. Not recognized.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the structure of a copper or copper alloy clad steel according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view showing the corrosion situation that occurs in a copper or copper alloy clad steel according to an embodiment of the present invention. FIG. 5 is a cross-sectional view showing the structure of conventional copper or copper alloy clad steel, and FIG. 4 is a cross-sectional view showing the corrosion situation that occurs in conventional copper or copper alloy clad steel. Sub-Agents 1) Meifuku Agent Ryo Hagiwara - Sub-Agent Atsuo Anzai Figure 1 Figure 3 Figure 2 Figure 4

Claims (1)

[Claims] A copper or copper alloy clad steel sheet, characterized in that a metal having a natural electrode potential nobler than that of the copper or copper alloy and having excellent corrosion resistance is interposed between the copper or copper alloy laminate and the base steel.