JPS6274099A - Steel sheet for can having superior weldability - Google Patents

Abstract

PURPOSE:To manufacture a steel sheet for cans having superior weldability by properly plating the front and rear sides of a steel strip with Zn or the like so as to form stripes in the lateral direction, forming uniform metallic Cr layers by plating and producing chromium oxide on the Cr layers. CONSTITUTION:The front and rear sides of a steel strip are plated with Zn, a Zn-Sn alloy, an Ni-Sn alloy or an Ni-P alloy at intervals corresponding to the diameter of cans by about 0.1-5.0g/m<2> so as to form stripes of about 6-10mm width in the lateral direction. The front and rear sides of the steel strip having the resulting metallic layers are uniformly plated with metallic Cr by about 10-200mg/m<2> and chromium oxide is produced on the Cr layers by about 5-50mg/m<2> (expressed in terms of Cr). Thus, a steel sheet for cans having superior weldability, rust and corrosion resistances is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a steel plate for cans having excellent weldability.

(Prior art) Examples of steel sheets for cans with excellent weldability include those in which the surface of the steel sheet is plated with tin and the upper layer is plated with chrome (Japanese Patent Publication No. 57-45478);
.theta. alloy plating 1): A layer is plated with tin in stripes, and chromium oxide is formed on the entire surface of the upper layer (Japanese Patent Publication No. 56-38492).

(Measures to be Solved by the Invention) The present invention seeks to provide a steel plate for cans that provides oil-soaked weldability of such striped agate wood.

(Means for Solving the Problem) The present inventors have developed a steel strip in the width direction of the front and back surfaces (・can diameter (・ζ
Z n + r'= n- in stripes with interstices:
E n alloy, Ni-Sn alloy, Ni-P alloy 1 i
Qf is applied to the upper layer and the entire surface of the steel sheet [metallic chrome plating is applied to the flute, and chromium oxide is formed on the upper layer, and steel sheet for cans with excellent weldability and steel strip are coated with Fe on the entire front and back surfaces. -Sn alloy, Ni, Sn, Ni-
One type of P is plated, and one type of Zn, Zn-Sn alloy, Ni-P%Ni-Sn alloy is plated in stripes on the top and bottom sides at intervals according to the can diameter. The present invention was completed by discovering a steel sheet for cans with excellent weldability, which has metal chromium plating applied to the upper layer and the entire surface of the steel strip, and furthermore, chromium oxide is formed on the upper layer.

In the present invention, a steel plate (band) is cut into blanks of a size corresponding to the can size, then formed into a cylindrical shape, and both ends are welded to form the can body. The above-mentioned Zn plating, etc., which has the effect of improving weldability, is applied, and the interval between the striped plating is determined depending on the size of the can, that is, the diameter of the can.

The width of the striped plating is determined by considering the welding lap allowance at both ends, shear accuracy during welding, etc.
A width of 6 to 10 U is sufficient. Also, the amount of plating is O,
1 to 5.0 f/rrt” (Ni-P plating is 0.
1-1. Oy/m”) is suitable, approximately O2]
If it is less than -2/a, the effect of improving welding p2 will be small;
Also about 5. t) Even if the welding speed is increased to 'i//m' or more, there is no proportional improvement in the effect of weldability, but rather it becomes disadvantageous in terms of cost.

The reason why such stripe plating completely improves weldability is that it has a lower melting point than the metal chromium etc. plated on the upper layer, so the stripe plating metal melts earlier than the metal chromium etc. due to the heat during welding, and the upper layer It is removed from the welding process together with the metal chromium etc. present in the welding area by the pressurized seal, and the welding position is almost completely free of metal chromium etc. which inhibits weldability, thereby improving weldability.

In addition, as such a stripe plating method, for example, as shown in Japanese Patent Application Laid-Open No. 60-21392, grooves are formed entirely in the width direction of the roll surface at intervals corresponding to the can diameter, and electrodes are placed at the bottom of the branch grooves. A pair of roll gold is provided, and plated I? While being filled with light, the rolls are rotated and the steel strip is used as a cathode, and the electrodes placed in the grooves are used as anodes, while the rolls are rotated and moved in contact with the rolls on each of the front and back sides of the steel strip, and stripe plating is applied to the steel strip. It is something.

However, such stripe plating may be performed by directly plating the steel strip, and then applying metal chrome plating or other metal plating as described below.Also, in order to improve the color tone, corrosion resistance, etc. of the metal chrome plating, the steel strip may be plated directly on the steel strip before stripe plating. Fe on the entire obi
-Sn alloy, Ni, Sn.

1 type from the instep of Nx-P etc.+1jQ0.03~0.5 f
/m' It can also be plated.

These platings, the above-mentioned stripe plating, can be advantageously performed under already known plating conditions (plating solution composition, current density, etc.).

Next, the metallic chromium applied to these upper layers is 10 to 200
mv/rr? (preferably from 60 to 120 mq/ri), it is possible to improve weldability and provide corrosion resistance as a can; when it is less than about 10 mq/rr, the corrosion resistance of the steel strip (plate) is poor; Moreover, if it exceeds about 200 m/m', the removal effect by stripe plating etc. will not be sufficient as mentioned above, and the weldability will be completely deteriorated, which is not preferable.

Furthermore, the chromium oxide produced in the upper layer has a content of 5 to 50
#I/d (the amount of Cr in the n2 compound) can improve weldability, corrosion resistance, etc. from the relationship between the stripe plating and the amount of gold-4 chromium plating.

Next, all examples of the present invention will be compared with 1 J and 1 J.

Note 1: Rust resistance was evaluated by the degree of rust that appeared on the surface of the test material after the test material was left standing in a factory or warehouse for 6 months (rust surface @ less than 1.0%). ○, 1.0% or more
0 m9/dr, violet A baked, end face tray sealed,
Scratch reaching the substrate with a cutter knife (S cm
X 5 crn), then 1.5% citric acid 1.5
The test material was immersed in 100 cc of % NaCl bath solution at 50° C. for 3 days, then washed with water, dried, and the coating film was peeled off using cellophane tape, and all measurements were taken during the peeling. (0.1 m during peeling
Less than A ○, 0.1 to 0.21Δ, 0.2 or more x) Note 3
: Color tone and appearance The color tone and appearance of the surface of the sample material were all visually inspected. .

(Brownish X, dark gray overall gloss ○) Note 4: Seam weldability was evaluated using a seam welder using a weldable copper wire as an intermediate electrode.

The test material was preheated at 210°C for 20 minutes. The welding conditions were a lap thickness of 0.6113, a pressure of 40 Kpf,
Speed 50 mpm, current frequency + 00 N
2. The evaluation criteria is determined by the width of the appropriate current range. The lower limit was determined by the weld strength, and the upper limit was determined by the occurrence of dust (molten iron protruding in the form of a splash). (The appropriate current range is 20OA or more, which poses no practical problem.) Note 5: Varnish drive plating width is 88 width.

Note 6: The Fe-Sn alloy used as the base plating was heat-treated after tin plating. (Fe 19% by weight, remaining Sn) Note 7 Costripe plated Ni-5n alloy (Ni 35% by weight, remaining 5n) Zn-Sn alloy (Zn 50% by weight, remaining Sn)
, Ni-P alloy cNlzx amount ratio, residual P) (Effects of the invention) According to the invention, a steel plate for cans having excellent weldability, rust resistance, corrosion resistance, etc. can be obtained.

In other words, the economic disadvantage of normal furisaku ($25 ET),
This is a steel plate for cans that solves the problems of weldability of thin ROM-plated steel plates, and provides great industrial benefits.

Claims (2)

[Claims] (1) Zn, Zn-Sn alloy, Ni-Sn alloy, Ni-
A steel sheet for cans with excellent weldability, which is plated with one of the P alloys, the upper layer and the entire surface of the steel strip are plated with metallic chromium, and chromium oxide is formed on the upper layer. (2) Fe-Sn alloy, Ni, Sn, on the entire front and back surfaces of the steel strip.
One type of Ni-P is plated, and the upper layer is coated with Zn and Zn-S in stripes at intervals according to the can diameter in the width direction of the front and back surfaces.
It is plated with one type of n-alloy, Ni-Sn alloy, or Ni-P alloy, and the upper layer and the entire surface of the steel strip are plated with metallic chromium, and furthermore, chromium oxide is formed on the upper layer, which has excellent weldability. Steel plate for cans.