GB/T 2522-2017Methods of test for the determination of coating insulation resistance and coating adhesion of electrical strip and sheet (English PDF)

11.2012 Magnetic Materials – Part 11. Method of Test for the Determination of Surface

Insulation Resistance of Magnetic Sheet and Strip; the consistency with IEC 60404-

11.2012 is not equivalent.

This Standard was proposed by China Iron and Steel Industry Association.

This Standard shall be under the jurisdiction of National Technical Committee for

Standardization of Steel (SAC/TC 183).

Drafting organizations of this Standard. Wuhan Iron and Steel Company Limited,

Baoshan Iron & Steel Co., Ltd., Shougang Corporation, and China Metallurgical

Information and Standardization Institute.

Chief drafting staffs of this Standard. Liu Jizhong, Shen Jie, Xiang Qian, Shi Jianrui,

Wang Yujie, Hu Shoutian, Tang Ling, Gong Jian, Liu Baoshi, Wei Haili, Zhou Xing, and

Qiu Yi.

Methods of Test for the Determination

of Coating Insulation Resistance and

Coating Adhesion of Electrical Strip and Sheet

2.1 Measurement principle

Franklin Method that can only perform single coating measurement shall be adopted.

The device circuit schematic diagram is shown in Figure 1. Under the specified voltage

and pressure, press 10 fixed-area metal contacts against a coating surface of the steel

plate. Evaluate the effectiveness of surface insulation coating by measuring the current

through 10 contacts.

Key.

Take ±5% or less test method determining the uncertainty to test the total force exerted

by all contacts on the specimen under test.

2.4 Device confirmation

The confirmation of the device is suitable to take the following three types.

a) Under the rated test pressure, apply the contacts and the drilling bit to a clean

copper plate; the total current through the 10 contacts shall be 1.0×(1±3%)A; if

the actual situation doesn't match, check the cleanliness of the contacts, the

sharpness of the drilling bit and the contact resistance.

b) Under the rated test pressure, pressure the carbon paper onto the white paper

through the contacts; at this time, even indentation occurs instead of the sign of

force concentration. Replace the carbon paper and white paper by a force

measurement board that exerts pressure and is displayed by changing the color

density.

c) Successively connect the 0.1ohm, 1ohm, 10ohm and 100ohm standard resistances in

between the drilling bit and contact pole-shoe; the indication value is stable and

reach the required current level.

2.5 Test procedures

2.5.1 Place the specimen between the test bench and 10 contacts; slower exert a

certain force. exert the force of 1290×(1±5%)N to the total area of 645mm2; exert the

force of 2000×(1±5%)N to the total area of 1000mm2, which is equivalent to the

pressure of 2N/mm2.

2.5.2 Power the electrode with a regulated power supply, and read the total current

(or read by the computer).

2.5.3 If the test is to evaluate the single-side coating insulation quality, take 10 data

by the 10 contacts on the 10 representative different areas or 10 test specimens.

2.5.4 If the test is a comprehensive evaluation of double-side coating insulation

quality, the 10 contacts shall be tested on 5 representative areas selected from one-

side of the steel plate or 5 test specimens; the two-side test shall not be performed

within the same area of the test specimen.

2.6 Calculation of coating insulation resistance

2.6.1 Surface insulation resistance coefficient

Introduce the 10 measured current values of the 10 parallel contacts into Formula (1),

calculate and obtain the surface insulation resistance coefficient (there are 10

measured values for single-side coating, or 5 measured values on each side of the

......