Refractory Castable for Rolling Mill Heating Furnaces

1 Scope

This document specifies the classification and grades, technical requirements, test methods, quality evaluation procedures, packaging, marking, and transportation of refractory castables for rolling mill heating furnaces. , Storage and certificate of quality.

This document is applicable to refractory castables used for working linings and insulation linings of rolling mill heating furnaces.

2 Normative References

The contents of the following documents are indispensable parts of this document through normative references in this document. , Referenced documents with dates , Only the version corresponding to the date is applicable to this document. ; Referenced documents without dates , Its latest version ( Including all amendments ) Applies to this document.

GB/T 4513.2   Refractory monolithic materials   Part 2 Sampling : GB/T 4513.5

Refractory monolithic materials Specimen preparation and pretreatment 5 Sampling : GB/T 4513.6

Determination of physical properties Specimen preparation and pretreatment 6 Sampling : GB/T 6900

Chemical analysis method for aluminum silicate refractory materials GB/T 15545

General provisions for packaging, marking, transportation, storage and certificates of quality of refractory monolithic materials GB/T 21114

Refractory materials X X-ray fluorescence spectrometry chemical analysis method for cast glass chips GB/T 30873

Thermal shock resistance test method X   GB/T 36134

Refractory monolithic materials, explosion resistance test method YB/T 4130

Thermal conductivity test method X   Water flow plate method ( Terms )

and definitions This document does not have any terms and definitions that need to be defined.

Classification and Grades

Refractory castables for rolling mill heating furnaces are divided into working lining refractory castables and insulation lining refractory castables according to their use. Working lining refractory castables are divided into seven grades: ZJ-40, ZJ-50, ZJ-60, ZJK-60, ZJ-65, ZJS-65, and ZJ-70, according to alumina content, performance characteristics, and use location; insulation lining refractory castables are divided into five grades: ZJQ-0.6, ZJQ-0.8, ZJQ-1.0, ZJQ-1.3, and ZJQ-1.5, according to bulk density.

Among them, Z, J, K, S, and Q are the first letters of the pinyin of the first Chinese characters of "rolling mill heating furnace", "castable", "explosion resistance", "water-cooled pipe", and "lightweight", respectively; the numbers after ZJ, ZJK, and ZJS represent the mass fraction of alumina in the product, and the numbers after ZJQ represent the bulk density of the product.

Technical Requirements

The physicochemical performance indicators of refractory castables for working linings of rolling mill heating furnaces shall conform to the provisions in Table 1.

The physicochemical performance indicators of refractory castables for insulation linings of rolling mill heating furnaces shall conform to the provisions in Table 2.

Table 1 Physicochemical performance indicators of refractory castables for working linings of rolling mill heating furnaces

6 Test methods

6.1 Sample preparation shall be carried out in accordance with GB/T 4513.5.

6.2 Determination of alumina content shall be carried out in accordance with GB/T 6900 or GB/T 21114.

6.3 Determination of bulk density, room temperature bending strength, room temperature compressive strength, and permanent linear change after heating shall be carried out in accordance with GB/T 4513.6.

6.4 Determination of thermal shock resistance shall be carried out in accordance with GB/T 30873.

6.5 Determination of burst resistance temperature shall be carried out in accordance with GB/T 36134.

6.6 Determination of thermal conductivity shall be carried out in accordance with YB/T 4130.

7 Quality assessment procedures

7.1 Batching

Products are batched according to the same grade. Each batch of refractory castable for working lining of rolling heating furnace shall not exceed 60t, and each batch of refractory castable for heat insulation lining of rolling heating furnace shall not exceed 50t.

7.2 Sampling and acceptance criteria

7.2.1 Sampling shall be carried out in accordance with GB/T 4513.2.

For refractory castables for working lining of rolling heating furnaces, the alumina content, room temperature compressive strength, permanent linear change after heating, and thermal shock resistance of ZJS-65 grade are acceptance inspection items; for refractory castables for heat insulation lining of rolling heating furnaces, the room temperature compressive strength, permanent linear change after heating, and thermal conductivity are acceptance inspection items. If any unqualified item is found in the inspection results, double samples shall be prepared according to 7.2.1 for re-inspection of the item. If the average value of the re-inspection results meets the requirements of Table 1 or Table 2, the batch of products shall be judged as qualified; otherwise, it shall be judged as unqualified.

7.3 Form of qualification assessment

Qualification assessment can be carried out in the form of supplier's declaration, user's determination or third-party certification.

8 Packaging, marking, transportation, storage and quality certificate

8.1 Packaging, marking, transportation and storage shall be carried out in accordance with GB/T 15545.

Upon shipment, a quality certificate issued by the quality supervision department shall be attached, indicating the supplier's name, purchaser's name, product name, document number, grade, batch number, batch size, production date, and physical and chemical index test results.

Upon shipment, product instructions shall be attached.

Refractory castable for rolling furnace

1 Range

This document specifies the classification and grade, technical requirements, test methods, quality assessment procedures, packaging, marking, transportation, storage and quality certificates of refractory castables for steel rolling heating furnaces.

This document applies to refractory castables for working linings and thermal insulation linings of steel rolling heating furnaces.

2 Normative reference documents

The contents of the following documents constitute the essential provisions of this document through the normative references in the text. Where a reference file with a date is noted, only the version corresponding to that date applies to this file; Undated references, the latest version of which (including all change orders) applies to this document.

GB/T 4513.2 Amorphous refractories – Part 2: Sampling

GB/T 4513.5 Amorphous refractories – Part 5: Sample preparation and preparation

GB/T 4513.6 Amorphous refractories – Part 6: Determination of physical properties

GB/T 6900 aluminum-silicon refractory chemical analysis method

GB/T 15545 General requirements for packaging, marking, transport, storage and quality certificates of amorphous refractory materials

GB/T 21114 refractories by X-ray fluorescence spectrochemical analysis of fused cast glass sheets

GB/T 30873 Test method for thermal shock resistance of refractories

GB/T 36134 Amorphous refractories – Test method for bursting resistance

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

3 Terms and definitions

There are no terms and definitions to be defined in this document.

4 Classification and brand

Refractory castables used in steel rolling heating furnaces can be divided into refractory castables for working lining and refractory castables for heat insulation lining according to the used parts. Work lining refractory castables according to alumina content, performance characteristics and use parts are divided into ZJ-40, ZJ-50, ZJ-60, ZJK-60, ZJ-65, ZJS-65, ZJ-70 seven grades; Heat insulation lining refractory castable is divided into ZJQ-0.6, ZJQ-0.8, ZJQ-1.0, ZJQ-1.3, ZJQ-1.5 five grades according to volume density.

Among them, Z, J, K, S, and Q are the first Chinese alphabetic initials of “steel rolling heating furnace”, “castable”, “anti-burst”, “water-cooling pipe”, and “light”, respectively; The numbers after ZJ, ZJK, ZJS indicate the quality fraction of the product alumina, and the number after ZJQ indicates the volume density of the product.

5 Technical Requirements

5.1 The physical and chemical properties of refractory castables used for the working lining of the steel rolling heating furnace shall conform to the provisions of Table 1.

5.2 The physical and chemical properties of refractory castables used for the heat insulation lining of the steel rolling heating furnace shall conform to the provisions of Table 2.

6 Test methods

6.1 Sample preparation was carried out according to GB/T 4513.5.

6.2 The alumina content is determined in GB/T 6900 or GB/T 21114.

6.3 The measurement of bulk density, flexural strength at room temperature, compressive strength at room temperature, and permanent line change of heating was carried out according to GB/T 4513.6.

6.4 Thermal shock resistance is measured according to GB/T 30873.

6.5 The anti-burst temperature was measured according to GB/T 36134.

6.6 Thermal conductivity was measured according to YB/T 4130.

7 Quality assessment procedures

7.1 Batch

The products shall be batched by the same grade; each batch of refractory castable for the working lining of the steel rolling heating furnace shall not exceed 60t, and each batch of refractory castable for the heat insulation lining of the steel rolling heating furnace shall not exceed 50t.

7.2 Rules for sampling and conformity determination

7.2.1 Sampling is performed according to GB/T 4513.2.

7.2.2 The alumina content, pressure strength at normal temperature, change of heating permanent line, and thermal shock resistance of ZJS-65 refractory castable used for working lining of steel rolling heating furnace are the acceptance inspection items; The pressure strength at normal temperature, change of heating permanent line, and thermal conductivity of refractory castable used for heat insulation lining of steel rolling heating furnace are the acceptance inspection items. If there are any unqualified items in the test results, the items shall be retested by re-sampling and preparing double samples according to 7.2.1. If the average value of the retest results conforms to the provisions of Table 1 or Table 2, the batch of products shall be judged to be qualified; otherwise, the products shall be disqualified.

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 Packaging, marking, transportation, and storage shall be carried out according to GB/T 15545.

8.2 When the products are issued, the quality certificate issued by the quality supervision department shall be attached, indicating the name of the supplier, the name of the demander, the name of the product, the number of this document, the brand number, the batch number, the production date, the physical and chemical index test results, etc.

8.3 When the product is shipped, it shall be accompanied by the product instruction manual.