GB/T 35845-2018 莫来石质隔热耐火砖/Insulating mullite refractory bricks

2024-07-11

莫来石质隔热耐火砖

1 范围

  本标准规定了莫来石质隔热耐火砖的术语和定义、牌号和形状尺寸、技术要求、试验方法、质量评定程序、包装、标志、运输、储存及质量证明书。

  本标准适用于热工窑炉隔热层或不直接接触高温熔融物料工作层的莫来石质隔热耐火砖。

2 规范性引用文件

  下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件,仅注日期的版本适用于本文件。凡是不注日期的引用文件,其最新版本(包括所有的修改单)适用于本文件。

  GB/T 2992.1 耐火砖形状尺寸 第1部分:通用砖

  GB/T 2998定形隔热耐火制品,体积密度和真气孔率试验方法

  GB/T 5072耐火材料 常温耐压强度试验方法

  GB/T 5988耐火材料 加热永久线变化试验方法

  GB/T 5989耐火材料 荷重软化温度试验方法示差升温法

  GB/T 6900铝硅系耐火材料化学分析方法

  GB/T 7321定形耐火制品试样制备方法

  GB/T 10325定形耐火制品验收抽样检验规则

  GB/T 10326 定形耐火制品尺寸、外观及断面的检查方法

  GB/T 16546 定形耐火制品包装、标志、运输和储存

  GB/T 21114耐火材料 X射线荧光光谱化学分析-熔融玻璃片法

  GB/T 32833隔热耐火砖抗剥落性试验方法

  YB/T 4130 耐火材料 导热系数试验方法(水流量平板法)

3 术语和定义

  下列术语和定义适用于本文件,

3.1

  莫来石质隔热耐火砖 insulating mullite refractory brick

  主晶相为莫来石相的铝硅系隔热耐火砖。

4 牌号和形状尺寸

4.1 牌号

  莫来石质隔热耐火砖按分级温度分为 MG-23、MG-25、MG-26、MG-27、MG-28、MG-30 和 MG-32.共七个牌号。其中,M、G分别为莫、隔的汉语拼音首字母,其后的数字代表莫来石质隔热耐火砖的分级,依据加热永久线变化的试验温度标定,具体含义如表1所示。

表1莫来石质隔热耐火砖的分级

级别

加热线变化≤2%时的试验温度/℃(℉)

MG-23

1230(2250)

MG-25

1350(2450)

MG-26

1400(2550)

MG-27

1450(2650)

MG-28

1510(2750)

MG-30

1620(2950)

MG-32

1730(3150)

4.2 形状尺寸

  砖的形状及尺寸应符合 GB/T 2992.1的规定,也可按需方图纸制造,

5 技术要求

5.1 砖的理化指标应符合表2的规定。

表2莫来石质隔热耐火砖的理化指标

项目

指标

MG-23

MG-25

MG-26

MG-27

MG-28

MG-30

MG-32

w((Al2O3)/%

μ0

40

50

55

60

65

70

77

σ

1.0

w(Fe2O3)/%

μ0

1.0

1.0

0.9

0.8

0.7

 0.6

0.5

σ

0.1

体积密度/(g/cm3)

μ0

0.55

0.80

0.85

0.90

0.95

1.05

1.35

σ

0.05

常温耐压强度/MPa

μ0

1.0

1.5

2.0

2.5

2.5

3.0

3.5

σ

0.2

0.5

1.0

μmin

0.9

1.3

1.8

2.2

2.2

2.7

3.2

加热水久线变化/%(T / ℃x12 h)

试验温度 T/℃

1230

1350

1400

1450

1510

1620

1730

Xmin~Xmax

-1.5~0.5

导热系数
[W/(m.K)] ≤
(平均温度±25℃)

200

0.18

0.26

0.28

0.32

0.35

0.42

0.56

350

0.20

0.28

0.30

0.34

0.37

0.44

0.60

600

0.22

0.30

0.33

0.36

0.39

0.46

0.64

0.05 MPa荷重软化温度T0.5/℃

1080

1200

1250

1300

1360

1470

1570

抗剥落性/%

提供数据

 

5.2 砖的尺寸允许偏差及外观应符合表3的规定。

表3莫来石质隔热耐火砖的尺寸允许偏差及外观 单位为毫米

项目

允许偏差

尺寸允许偏差

尺寸≤250

±1.0

尺寸251~400

±1.5

扭曲

尺寸101~250

0.8

尺寸251~400

1.0

缺角长度(a+b+c)

35

缺棱长度(e+f+g)

55

熔洞直径

5.0

裂纹长度

宽度≤0.25

不限制

宽度0.26~0.5

30

宽度>0.5

不准有

相对边差

厚度

1.0

注1:根据用户需求可对砖的一个主要尺寸进行分档。
注2:对于特异型制品的允许裂纹长度由供需双方另行约定。

 

6试验方法

6.1砖的检验制样按 GB/T 7321 进行。

6.2化学成分的测定按 GB/T 6900 或按 GB/T 21114 进行。

6.3体积密度的测定按 GB/T 2998 进行。

6.4常温耐压强度的测定按 GB/T 5072 进行。

6.5加热永久线变化的测定按 GB/T 5988 进行。

6.6导热系数的测定按 YB/T 4130(水流量平板法)进行。

6.7荷重软化温度的测定按 GB/T 5989 进行、

6.8抗剥落性的测定按 GB/T 32833 进行。

6.9 砖的尺寸、外观及断面的检査按 GB/T 10326 进行。

7质量评定程序

7.1 组批

  砖应按同一牌号进行组批,每批不超3万块。

7.2 抽样及验收

  砖的抽样与验收按 GB/T 10325 进行

  体积密度、常温耐压强度、加热永久线变化和导热系数(平均温度为 350 ℃)为验收检验项目

7.3 合格评定形式

  合格评定可采用供货方声明、使用方认定或第三方认证的形式进行。

8 包装、标志、运输、储存及质量证明书

8.1 砖的包装、标志、运输和储存按 GB/T 16546 规定进行:特殊情况由供、需双方另行约定。

8.2 产品发出时,应附有供方质量部门签发的质量证明书,载明:供方名称、需方名称、发货日期、合同号、产品名称、适用标准号、牌号、砖号及理化指标检验结果等。

 

 

 

 

Insulating mullite refractory bricks

1 Range

  This standard specifies the terms and definitions, grades and shapes, technical requirements, test methods, quality assessment procedures, packaging, marking, transportation, storage and quality certificates of mullite heat-insulating firebricks.

  This standard applies to mullite insulated firebricks for thermal kiln insulation or working layers that are not in direct contact with high temperature molten materials.

2 Normative reference documents

  The following documents are essential for the application of this document. For dated references, the date-only version applies to this document. For undated references, the latest version (including all amendment orders) applies to this document.

  GB/T 2992.1 Shape and dimensions of refractory bricks – Part 1: general purpose bricks

  GB/T 2998 shaped heat-insulating refractory products — Test method for bulk density and true porosity

  GB/T 5072 refractories – normal temperature compressive strength test method

  GB/T 5988 refractory heating permanent line change test method

  GB/T 5989 refractories load softening temperature test method differential rising temperature method

  GB/T 6900 aluminum-silicon refractory chemical analysis method

  GB/T 7321 shaped refractory product sample preparation method

  GB/T 10325 shaped refractory products acceptance sampling inspection rules

  GB/T 10326 shaped refractory products size, appearance and section inspection method

  GB/T 16546 shaped refractory products packaging, marking, transportation and storage

  X-ray fluorescence spectrochemical analysis of GB/T 21114 refractories – molten glass sheet method

  GB/T 32833 Test method for spalling resistance of heat-insulating refractory bricks

  Test method for thermal conductivity of YB/T 4130 Refractories (Water flow plate method)

3 Terms and definitions

  The following terms and definitions apply to this document,

3.1

  Insulating mullite refractory brick

  Aluminum-silicon heat-insulating refractory brick with mullite main crystalline phase.

4 Grades and shapes

4.1 Brand

  Mullite heat insulation refractory bricks are divided into MG-23, MG-25, MG-26, MG-27, MG-28, MG-30 and MG-32 according to grading temperature. There are seven brands. Among them,M and G are the Chinese pinyin initial letters of Mo and Geu respectively, and the numbers after them represent the classification of Mullite heat-insulating firebricks, which are calibrated according to the test temperature of the change of the heating permanent line, the specific meanings are shown in Table 1.

Table 1 Classification of mullite heat-insulating refractory bricks

Rank

Test temperature when heating wire changes ≤2%/℃(℉)

MG-23

1230(2250)

MG-25

1350(2450)

MG-26

1400(2550)

MG-27

1450(2650)

MG-28

1510(2750)

MG-30

1620(2950)

MG-32

1730(3150)

4.2 Shape and Size

The shape and size of the brick shall comply with the provisions of GB/T 2992.1, and can also be manufactured according to the drawings of the customer.

5 Technical Requirements

5.1 The physical and chemical indexes of bricks shall comply with the provisions of Table 2.

Table 2 Physical and chemical indexes of mullite heat-insulating refractory bricks

Item

Index

MG-23

MG-25

MG-26

MG-27

MG-28

MG-30

MG-32

w((Al2O3)/%

μ0

40

50

55

60

65

70

77

σ

1.0

w(Fe2O3)/%

μ0

1.0

1.0

0.9

0.8

0.7

 0.6

0.5

σ

0.1

Bulk density/(g/cm3)

μ0

0.55

0.80

0.85

0.90

0.95

1.05

1.35

σ

0.05

Compressive strength at room temperature/MPa

μ0

1.0

1.5

2.0

2.5

2.5

3.0

3.5

σ

0.2

0.5

1.0

μmin

0.9

1.3

1.8

2.2

2.2

2.7

3.2

Heating water long line change/%(T / ℃x12 h)

Test temperature T/℃

1230

1350

1400

1450

1510

1620

1730

Xmin~Xmax

-1.5~0.5

Thermal conductivity[W/(m.K)] ≤
(Mean temperature±25℃)

200

0.18

0.26

0.28

0.32

0.35

0.42

0.56

350

0.20

0.28

0.30

0.34

0.37

0.44

0.60

600

0.22

0.30

0.33

0.36

0.39

0.46

0.64

0.05 MPaSoftening temperature under loadT0.5/℃

1080

1200

1250

1300

1360

1470

1570

Resistance to spalling/%

Provide data

5.2 The permissible size deviation and appearance of the brick shall comply with the provisions of Table 3.

Table 3 Size tolerance and appearance of mullite heat-insulating refractory brick Unit in millimeter

Item

Allowable deviation

Allowable deviation of dimension

Dimension≤250

±1.0

Dimension251~400

±1.5

Contort

Dimension101~250

0.8

Dimension251~400

1.0

Missing Angle length(a+b+c)

35

Missing edge length(e+f+g)

55

Hole diameter

5.0

Crack length

Breadth≤0.25

No limit

Breadth0.26~0.5

30

Breadth>0.5

Be forbidden from

Relative edge difference

Thickness

1.0

Note 1: A major size of brick can be graded according to user requirements.

Note 2: The allowable crack length for special shaped products shall be separately agreed by the supply and demand parties.

6 Test methods

6.1 Bricks shall be inspected and prepared according to GB/T 7321.

6.2 Chemical composition shall be determined according to GB/T 6900 or GB/T 21114.

6.3 The bulk density was measured according to GB/T 2998.

6.4 The compressive strength at room temperature shall be measured according to GB/T 5072.

6.5 The determination of permanent line change of heating was performed according to GB/T 5988.

6.6 Thermal conductivity was measured according to YB/T 4130(water flow plate method).

6.7 The load softening temperature is measured according to GB/T 5989.

6.8 The stripping resistance was measured according to GB/T 32833.

6.9 The inspection of size, appearance and section of bricks shall be carried out according to GB/T 10326.

7 Quality assessment procedures

7.1 Batch

  Bricks should be grouped according to the same grade, with each batch not exceeding 30,000 pieces.

7.2 Sampling and acceptance

  Sampling and acceptance of bricks shall be carried out according to GB/T 10325

Bulk density, compressive strength at room temperature, permanent line change in heating and thermal conductivity (average temperature 350 ℃) are the acceptance test items

7.3 Form of conformity assessment

The conformity assessment can be made in the form of the supplier’s declaration, the user’s certification or the third party’s certification.

8 Packing, marking, transportation, storage and quality certificate

8.1 The packaging, marking, transportation and storage of bricks shall be carried out in accordance with the provisions of GB/T 16546: in special cases, the supply and demand shall be separately agreed by both parties.

8.2 When the products are shipped, the quality certificate issued by the quality department of the supplier shall be attached, indicating the name of the supplier, the name of the demander, the date of delivery, the contract number, the name of the product, the applicable standard number, the brand number, the brick number and the test result of physical and chemical index.