US 4,047,977 AGrant
Method of Continuous Galvanizing Steel Strip on Partial or One Side
Issue Date:1977-09-13
•9 Claims
•2 Drawing Sheets
Abstract
A method of continuous galvanizing a steel strip partially or one side, which comprises applying silicone resin to a part or on one side of the steel strip which is to be left non-plated in a subsequent continuous molten zinc coating, baking the silicon resin coated steel strip at a temperature ranging from 300 to 800.degree. C in an oxidizing atmosphere, and subjecting the steel strip to heat treatment in a reducing atmosphere and introducing the heat treated steel strip to a zinc coating bath.
Metadata
Assignee
- Nippon Steel Corporation
Inventors
- Katsuyoshi Yoshida
- Yukio Kitajima
Application Information
Application Number:US 6274722
Filing Date:1975-10-30
Priority Date:1972-05-04
Art Unit:165
Classifications
IPC:
C23C 102
Field of Search:
427148134328;329;330;321;300;226;95;282-2876.238
Patent Drawings (2 sheets)
Description
Next, one example of the apparatus for practising the present invention will be described referring to the attached drawing.
In FIG. 1, the steel strip 2 is uncoiled from the steel strip coil 1, one side of the steel strip 2 is applied with the silicone resin by means of the coating roll 3 (a spray may be used also), then the resin coated steel strip 2 is baked at a temperature ranging from 300.degree. to 800.degree. C in the oxidizing furnace 7, then annealed in the reducing pretreatment equipment 4 and introduced into the hot dipping bath 5 where it is coated with zinc on the other side, the amount of the zinc coating is controlled, and finally the silicone resin coating is removed from the strip furnace by means of the brushing roll 6 and the strip is coiled.
The present invention will be more clearly understood from the following examples.
Examples of the present invention will be set forth under. These examples were conducted using the above illustrated production apparatus.
Claims
What is claimed is:
1. A method of continuous galvanizing a steel strip partially or one side, which comprises applying a silicone resin selected from the group consisting of polysilalkylenes and polysiloxanes to a part or on one side of the steel strip which is to be left non-plated in a subsequent continuous molten zinc coating, baking the silicone resin coated steel strip at a temperature ranging from 300.degree. to 800.degree. C for 2 to 30 seconds in an oxidizing atmosphere to deposit a masking film, and subjecting the steel strip to heat treatment in a reducing atmosphere and introducing the heat treated steel strip to a zinc coating bath.
2. A method according to claim 1, in which the silicone resin is coated in an amount of 0.5-50 g/m.sup.2 as the resin content.
3. A method according to claim 1, in which one or more members selected from the group consisting of metallic oxides, metallic hydroxides, metallic nitrides, metallic carbides, metallic carbonates, metallic phosphates and metallic silicates is added to the silicone resin.
4. A method according to claim 3, in which the amount of the additive to the silicone resin is less than 50% by weight.
5. A method according to claim 1, in which the residual resin coating, after plating, is removed by acid pickling in an HCl solution.
6. A method according to claim 1, in which the residual resin coating, after plating, is removed by etching with chromate treating liquid effective to prevent white rust on zinc coated steel plates.
7. A method according to claim 1, in which the residual resin coating, after plating, is removed by brushing.
8. A method according to claim 1, in which the residual resin coating, after plating, is removed by acid pickling in an H.sub.2 SO.sub.4 solution.
9. A method according to claim 1 wherein the baking temperature is between 400.degree. and 800.degree. C.
Patent Citations (6)
| Patent | Date | Inventor | Cited By |
|---|---|---|---|
| US2498485 | 1950-02-01 | Clawson | |
| US2743192 | 1956-04-01 | White | |
| US2894850 | 1959-07-01 | Greene et al. | |
| US3055776 | 1962-09-01 | Stevenson et al. | |
| US3177085 | 1965-04-01 | Adams | |
| US3758388 | 1973-01-01 | Shotten |