Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces Methods of Test for the Determination of Surface Insulation Resistance and Lamination Factor of Electric Sheet and Strip (GB/T 2522-2007); the following changes have been made with respect to GB 2522-2007:
——the standard name is changed to Methods of Test for The Determination of Coating Insulation Resistance and Coating Adhesion of Electrical Strip and Sheet from Methods of Test for the Determination of Surface Insulation Resistance and Lamination Factor of Electric Sheet and Strip;
——the coating insulation resistance test circuit diagram is modified;
——the coating insulation resistance test circuit diagram is modified;
——the test method in which the total area of 10 contacts is 1000mm2 is added;
——the requirements on the total current of 10 contacts are modified;
——the calculation for coefficient of interface resistance is added;
——the repeatability and reproducibility requirements on coating insulation resistance test are added;
——coating adhesion levels are added.
This standard has been redrafted and modified adoption of Magnetic Materials - Part 11: Method of Test for the Determination of Surface Insulation Resistance of Magnetic Sheet and Strip (IEC 60404-11:2012), and it is not equivalent to IEC 60404-11:2012.
This standard is proposed by China Iron and Steel Industry Association.
This standard is under the jurisdiction of the National Technical Committee on Iron and Steel of Standardization Administration of China (SAC/TC 183).
The previous editions of the standard replaced by this standard are as follows:
——GB/T 2522-1981, GB/T 2522-1988, GB/T 2522-2007.
Methods of Test for the Determination of Coating Insulation Resistance and Coating Adhesion of Electrical Strip and Sheet
1 Scope
This standard specifies methods of test for the determination of coating insulation resistance and coating adhesion of electrical strip and sheet.
This standard is applicable to the test for the determination of surface insulation resistance and interface resistance of non-oriented and oriented electrical strip and sheet, as well as the test for the determination of insulation coating adhesion of non-oriented and oriented electrical strip and sheet.
2 Test of Coating Insulation Resistance
2.1 Principle of measurement
The principle of the measurement is based on, and includes, the method originally described by Franklin which characterizes only one coated surface at a time.
The arrangement of the apparatus is shown in Figure 1. Ten metallic contacts of fixed area are applied to one coated surface of the sheet, under specified conditions of voltage and pressure. The effectiveness of the surface insulation is assessed by the measurement of the currents through the 10 contacts.
Keys:
1——d.c. power supply;
2——computer;
3——display;
4——10 contacts;
5——drill;
6——test specimen;
7——insulation coating.
Figure 1 Arrangement of Apparatus for the Measurement of Surface Insulation Resistance
Contacts are fed from a d.c. power supply, as shown in Figure 2, and the voltage between the 5×(1±1%)Ω resistor and the drill is stabilized at 500×(1±0.5%)mV over a current range of 0~1A. The two twist drills perform the function of current return contacts with the metallic substrate of test specimen.
2.2 Test specimen
2.2.1 Each test specimen shall be formed from a single sheet or length of strip. The width and length of the test specimen shall be respectively greater than the width and length of the contact assembly described in 2.3. This measurement is destructive; the test specimen can only be used once.
2.2.2 To obtain a representative result, test specimens shall be taken from the full sheet width. The test specimen surface shall be clean, flat and neat, and be free from any spot and scratch.
2.3 Apparatus
2.3.1 Contact assembly
The test specimen is pressed between a plate and the contact assembly. The contact assembly consists of 10 vertically-mounted metallic rods which move axially against springs in amounting block. These 10 contact rods are normally arranged in two rows. However, for convenience these 10 contacts can be arranged in one row. Each rod shall be provided with a contact button of bronze or other suitable material (for example, stainless steel) and shall be electrically insulated from the mounting frame.
Note 1: articulation of contact buttons improves contact by compensating for minor misalignments.
Each of the 10 contacts shall have a contact area of 64.5×(1±1%)mm2 or 100×(1±1%)mm2, giving a total area for the 10 contacts of 645×(1±1%)mm2 or 1000×(1±1%)mm2, and the recommended total area is 645 mm2.
Note 2: only the total area of 645 mm2 is adopted in international standard. Generally, the testing results of corresponding contacts of two total areas are not comparable.
Electrical contact with the substrate of the test specimen shall be achieved by means of two spring-loaded twist drills of about 3 mm diameter which pierce the insulation coating
2.3.2 Power supply
A d.c. power supply capable of maintaining a stabilized voltage of 500mV across the electrodes at the maximum load current of 1.0A shall be used.
2.3.3 Current measurement
The current flowing through the contact buttons shall be measured with an uncertainty of ± 2% or better. This can be achieved by inserting an ammeter in the supply to the contact buttons, at a point outside the connection to the stabilizing circuit.
The electrical arrangements of the stabilizing circuit and current measurement system are shown in Figure 2.
Keys:
1——Stabilized d.c. power supply;
2——drills;
3——contact;
4——output voltage;
5——feedback voltage;
6——test specimen.
Figure 2 Arrangement of Circuit
2.3.4 Determination of applied force
The total force applied by all of the contacts pressing on the test specimen shall be determined by any suitable means with an uncertainty of ±5 % or better.
2.4 Calibration
The calibration of the equipment should be checked in three ways:
a) The contacts and drills shall be applied to a clean copper sheet at nominal testing pressure. The total current passing through the 10 electrodes shall be 1.0×(1±3%)A. If this is not the case, the contacts shall be checked for cleanliness and the drills checked for sharpness and contact resistance.
b) Carbon paper pressed onto white paper by the contacts at nominal testing pressure shall give a set of even smudges free from signs of force concentration. Pressure measurement sheets that could indicate applied pressure as colour density variations can be used instead of the carbon paper and white paper.
c) Standard resistors of 0.1 Ω, 1 Ω, 10 Ω and 100 Ω connected between the drills and each contact button in turn shall be used to show that the stabilization is adequate and that the required current levels can be achieved.
2.5 Measuring procedure
2.5.1 The test specimen shall be positioned between the baseplate and the 10 contacts and a force of 1290×(1±5%)N for the total area of 645 mm2 or 2000×(1±5%)N for the total area of 1000mm2 shall be gradually applied. This corresponds to a pressure of 2 N/mm2.
2.5.2 The stabilized voltage supply shall be applied to the electrodes and the total current shall be recorded or by computer.
2.5.3 If the insulation quality of a single surface is to be evaluated in the test, 10 readings shall be taken using the 10 contacts on 10 separate representative areas of the sheet or on 10 test specimens.
2.5.4 If the insulation quality of both surfaces is to be jointly evaluated in the test then ten applications of the contacts shall be made to each surface on five separate representative areas or test specimens. The same area of the test specimen shall not be used to test both sides.
2.6 Calculation of coating insulation resistance
2.6.1 Coefficient of surface insulation resistance
The coefficient of surface insulation resistance shall be determined by inserting the 10 values of the current flowing through the 10 electrodes in parallel (either all from one surface or five from each of the two coated surfaces) in Formula (1).
(1)
Where,
C——the coefficient of surface insulation resistance, in Ω·mm2/side or Ω·cm2/side;
A——the total area of the 10 contacts, in mm2 or cm2;
U——the voltage applied to the contacts and 5 Ω resistors, in V;
R——the resistance in series with each contact, equal to 5 Ω, in Ω;
IA——the measured total electrode current (10 values), in A;
2.6.2 Coefficient of interface resistance
Value RA represented by coefficient of interface resistance is the resistance of the two surfaces of the product, it is theoretically twice of the coefficient of surface insulation resistance (C).
The coefficient of interface resistance shall be determined by inserting the 10 values of the current flowing through the 10 electrodes in parallel (five from each of the two coated surfaces, 10 values in total) in Formula (2).
(2)
Where,
RA——the coefficient of interface resistance, in Ω·mm2/sheet or Ω·cm2/sheet;
A——the total area of the 10 contacts, in mm2 or cm2;
U——the voltage applied to the contacts and 5 Ω resistors, in V;
R——the resistance in series with each contact, equal to 5 Ω, in Ω;
IA——the measured total electrode current (10 values), in A;
2.7 Repeatability and reproducibility
Even when equipment, operation and maintenance, etc. are in good condition, their repeatability and reproducibility are greatly affected by the surface properties of the test specimen when testing coating insulation resistance by Franklin's method. In actual test, it is very difficult evaluate the repeatability and reproducibility of the method.
2.8 Test report
Unless otherwise agreed, the test report shall include:
a) The number of this standard;
b) The identification and status of test specimen and coating;
c) The total area of the contacts of the selected equipment, 645 mm2 or 1000 mm2;
d) Test result: the coefficient of surface insulation resistance or the coefficient of interface resistance.
3 Test Method for Coating Adhesion
3.1 Apparatus
Brass cylinders with smooth surface and in diameter of 10mm, 20mm and 30mm respectively and the tolerance of -0.5 mm~+0.1 mm are used.
3.2 Test specimen
Representative test specimens shall be taken in the direction parallel to the rolling direction, not be less than 40mm from the edge of steel strip (sheet), without damaging test specimen coating. Dimensions of test specimen: 30 mm±0.2 mm in width and 280 mm~320 mm in length. The supplier and the purchaser can negotiate about special requirements, if any.
Foreword i
1 Scope
2 Test of Coating Insulation Resistance
3 Test Method for Coating Adhesion
ICS 77.040.99
H 21
中华人民共和国国家标准
GB/T 2522—2017
代替GB/T 2522—2007
电工钢带(片)涂层绝缘电阻和附着性测试方法
Methods of test for the determination of coating insulation resistance and coating adhesion of electrical strip and sheet
(IEC 60404-11:2012,Magnetic materials—Part 11:Method of test for the determination of surface insulation resistance of magnetic sheet and strip,NEQ)
2017-07-12发布 2018-04-01实施
中华人民共和国国家质量监督检验检疫总局
中国国家标准化管理委员会
发布
前言
本标准按照GB/T 1.1—2009给出的规则起草。
本标准代替GB/T 2522—2007《电工钢片(带)表面绝缘电阻、涂层附着性测试方法》,与GB/T 2522—2007相比,主要变化如下:
——标准名称由《电工钢片(带)表面绝缘电阻、涂层附着性测试方法》改为《电工钢带(片)涂层绝缘电阻和附着性测试方法》;
——修改了涂层绝缘电阻测试电路图;
——删除了涂层绝缘电阻测试的方法B;
——增加了10个触头总面积为1 000 mm2的测试方法;
——修改了10个触头的总电流的规定;
——增加了层间电阻系数的计算;
——增加了涂层绝缘电阻测试重复性和再现性要求;
——增加了涂层附着性级别。
本标准使用重新起草法参考IEC 60404-11:2012《磁性材料 第11部分:测定磁性钢板带表面绝缘电阻的测试方法》编制,与IEC 60404-11:2012的一致性程度为非等效。
本标准由中国钢铁工业协会提出。
本标准由全国钢标准化技术委员会(SAC/TC 183)归口。
本标准起草单位:武汉钢铁股份有限公司、宝山钢铁股份有限公司、首钢总公司、冶金工业信息标准研究院。
本标准主要起草人:刘集中、沈杰、向前、石建锐、王玉婕、胡守天、唐灵、龚坚、刘宝石、魏海丽、周星、邱忆。
本标准所代替标准的历次版本发布情况为:
——GB/T 2522—1981、GB/T 2522—1988、GB/T 2522—2007。
电工钢带(片)涂层绝缘电阻和附着性
测试方法
1 范围
本标准规定了电工钢带(片)涂层绝缘电阻和附着性的测试方法。
本标准适用于无取向和取向电工钢带(片)表面绝缘电阻和层间电阻的测试,以及无取向和取向电工钢带(片)绝缘涂层附着性的测试。
2涂层绝缘电阻的测试
2.1 测量原理
采用只能进行单涂层测量的富兰克林法。
设备电路示意图如图1所示。在规定的电压和压强下,将10个固定面积的金属触头压在钢板的一个涂层表面上。通过测量流过10个触头的电流来评定表面绝缘涂层的效能。
说明:
1——直流电源;
2——计算机;
3——显示器;
4——10个触头;
5——钻头;
6——试样;
7——绝缘涂层。
图1 表面绝缘涂层电阻测量电路示意图
触头由直流电源供电,如图2所示,5×(1±1%)Ω电阻和钻头间的电压在电流0~1 A的范围内稳定在500×(1±0.5%)mV。两个螺旋钻头的作用是与试样金属基板接触构成电流回路。
2.2试样
2.2.1 每个试样应由一个样片或一段样带构成。试样的长度和宽度应分别大于2.3所述的触头部件的长度和宽度。测试是破坏性的,试样只能使用一次。
2.2.2为了得到具有代表性的结果,试样应从钢板的整个宽度上剪取。试样表面应清洁、平整、无斑痕和划痕。
2.3测试装置
2.3.1触头部件
待测试样被压在平板底座和触头部件之间,触头部件由10根垂直安装的金属杆组成,这些金属杆可压缩弹簧在固定的单元内轴向移动。这10个触头通常排成两行,为方便使用也可排成一行。每根杆的端部由一个用青铜或其他合适的材料(如不锈钢)做的触头极靴.并与框架绝缘。
注1:万向连接方式的极靴可通过小范围补偿触头的角度偏差,改善电接触。
10个触头中的每一个触头的面积选用64.5×(1±1%)mm2或100×(1±1%)mm2,10个触头的总面积为645×(1±1%)mm2或1 000×(1±1%)mm2,推荐的触头总面积为645 mm2。
注2:国际标准只采用触头总面积645 mm2。两种总面积对应触头的检测结果通常不具有可比性。
通过弹簧加载的直径大约为3 mm的两个钻头钻穿试样的绝缘涂层,使钻头与试样金属基板形成电接触。
2.3.2 电源
应使用最大负载电流为1.0 A的直流稳压电源,确保两电极间电压稳定在500 mV。
2.3.3 电流测试
以±2%或更小的测量不确定度的方法测试流过触头极靴的电流。这可以在稳压电源的输出端与触头极靴之间靠近电源一侧接入一只电流表。
稳压电路和电流测试系统电路原理图如图2所示。
说明:
1——直流稳压电源;
2——钻头,
3——触头;
4——输出电压;
5——反馈电压;
6——试样。
图2电路示意图
2.3.4外加力的测定
应以±5%或更小的测量不确定度的合适的方法测试所有触头施加在待测试样上的合力。
2.4设备确认
设备的确认宜采用以下三种形式:
a)在额定试验压力下,把触头和钻头施加于洁净的铜板上,流过10个触头的总电流应是1.0×(1±3%)A,如果实际情况与之不符,应检查触头的清洁度、钻头的锐度和接触电阻。
b)在额定试验压力下,通过触头把复写纸压在白纸上,这时应出现均匀的压痕。而没有力集中的痕迹。可用颜色密度变化显示施加压力的力度测量板来代替复写纸和白纸。
c) 依次把0.1 Ω、1 Ω、10 Ω和100 Ω的标准电阻连接到钻头与触头极靴之间,示值稳定,并达到所要求的电流水平。
2.5测试步骤
2.5.1 把试样放在试样台和10个触头之间,缓慢施加一定的力:对于645 mm2的总面积施加1 290×(1±5%)N的力,对于1 000 mm2的总面积施加2 000×(1±5%)N的力,相当于2 N/mm2压力。
2.5.2 以稳压电源对电极供电,并读取总电流(或由计算机读取)。
2.5.3如果测试是评价单面的涂层绝缘质量,应使10个触头在钢板的10个具有代表性的不同区域或者10个测试样上测取10个数据。
2.5.4如果测试是综合评价双面涂层的绝缘质量,则应使用10个触头在钢板的每一面选取5个具有代表性的不同区域或者在5个测试试样上进行测试,在测试试样的同一个区域不应进行两面的测试。
2.6涂层绝缘电阻的计算
2.6.1 表面绝缘电阻系数
将10个并联触头10次测量的电流值代入式(1)。计算得出表面绝缘电阻系数(单面涂层10次测量值,或涂层上下表面每个面各5次测量值)。
…………………………(1)
式中:
C——表面绝缘电阻系数,单位为欧姆平方毫米每面(Ω·mm2/面)或欧姆平方厘米每面(Ω·cm2/面);
A——10个触头的总面积,单位为平方毫米(mm2)或平方厘米(cm2);
U——施加在触头和5 Ω电阻上的电压,单位为伏特(V);
R——与每个触头串联的电阻,等于5 Ω,单位为欧姆(Ω);
IA——每次测量的总电流(10个数值),单位为安培(A)。
2.6.2层间电阻系数
层间电阻系数表示的RA值代表了产品上下两个表面电阻值,理论上是表面绝缘电阻系数C的2倍。
将10个并联触头10次测量的电流值代入式(2),计算得出层间电阻系数(涂层面每面5次测量值,两个面共10次测量值)。
………………………(2)
式中:
RA——层间电阻系数,单位为欧姆平方毫米每片(Ω·mm2/片)或欧姆平方厘米每片(Ω·cm2/片);
A——10个触头的总面积,单位为平方毫米(mm2)或平方厘米(cm2);
U——施加在触头和5 Ω电阻上的电压,单位为伏特(V);
R——与每个触头串联的电阻,等于5 Ω,单位为欧姆(Ω);
IA——每次测量的总电流(10个数值),单位为安培(A)。
2.7重复性和再现性
即使设备及操作和维护等都处于良好状态时,用富兰克林法测试涂层绝缘电阻,其重复性和再现性很大程度上受试样表面特性的影响。在实际测试中很难评估方法的重复性和再现性。
2.8测试报告
测试报告至少包括以下信息,除非另有约定:
a)本标准编号;
b)试样和涂层的标识和状态;
c) 选用设备的触头总面积,645 mm2或1 000 mm2;
d)测试结果:表面绝缘电阻系数或层间电阻系数。
3涂层附着性的测试方法
3.1 装置
装置是直径分别为10 mm、20 mm、30 mm,公差为-0.5 mm~+0.1 mm的表面光滑的黄铜圆柱体。
3.2试样
在离钢带(片)边部不小于40 mm的地方,沿平行于轧制方向剪切具有代表性的试样,不得损伤试样涂层。试样的尺寸:宽度为30 mm±0.2 mm,长度为280 mm~320 mm。如有特殊要求,供需双方协商确定。
3.3测试
在室温下,将试样紧紧围绕黄铜圆柱体弯曲180°,再将弯曲后的试样扳直,检查试样内表面涂层的剥落情况。一般最先使用20 mm黄铜圆柱体弯曲,如必要再使用10 mm或30 mm黄铜圆柱体弯曲。
3.4评级
如无特殊要求,钢带(片)涂层绝缘附着性按表1评级。
表1 涂层附着性评级表
涂层级别 弯曲直径
10 mm 20 mm 30 mm
A 无脱落 无脱落
B 稍有脱落
C 脱落 稍有脱落 无脱落
D 脱落 无脱落
E 稍有脱落
F 脱落
注:稍有脱落是指试样弯曲后再将其扳直,目视可见的少量剥落。
3.5测试报告
测试报告至少包括以下信息,除非另有约定:
a)本标准编号;
b)试样和涂层的标识和状态;
c)测试结果:涂层级别。