GB/T 20567-2020Vanadium-nitrogen alloy (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 20567-2006 "Vanadium Nitrogen Alloy". Compared with GB/T 20567-2006, the main technical changes of this standard as follows:

---The reference standard for chemical analysis methods of vanadium-nitrogen alloys has been added (see Chapter 2);

--- Include VN19 brand products into the standard (see 3.1);

---Modified the vanadium content requirements of VN12 and VN16 products (see 3.1,

3.1 in the.2006 edition);

---Modified the particle size requirements of the product (see 3.3, the.2006 edition of 3.3);

---Modified sampling and sample preparation methods (see 4.1, 4.2,

4.1 in.2006 edition);

---Modified the particle size determination method (see 4.5,

4.4 in the.2006 edition);

---Modified the batch requirements (see 5.1,

5.2 of the.2006 edition);

---Modified the packaging, marking, storage, transportation and quality certificate regulations (see Chapter 6, Chapter 6 of the.2006 edition). This standard was proposed by the China Iron and Steel Association. This standard is under the jurisdiction of the National Pig Iron and Ferroalloy Standardization Technical Committee (SAC/TC318). Drafting organizations of this standard. Pangang Group Co., Ltd., Hegang Chengde Vanadium and Titanium New Materials Co., Ltd., Chengde Yanbei Metallurgical Materials Co., Ltd., National Vanadium and Titanium Products Quality Supervision and Inspection Center, China Metallurgical Construction Research Institute Co., Ltd., Metallurgical Industry Information Standards Institute. The main drafters of this standard. Zhou Kaizhu, Li Xiufeng, Wang Yonggang, Li Lanjie, Wang Xueyuan, Peng Yicun, Huang Pingsheng, Bai Fengren, Liu Yajian, Yang Xinneng, Fang Lin, Lu Mingliang, Huang Xiaoli, You Benyin, Lu Chunsheng. The previous versions of the standard replaced by this standard are as follows:

---GB/T 20567-2006. Vanadium Nitrogen Alloy

1 Scope

China's national product standard for vanadium-nitrogen alloy. It specifies the technical requirements, the test methods, the inspection rules, the packaging, marking, storage and transport and the quality certificate, and it applies to vanadium-nitrogen alloy used in steelmaking and casting. Vanadium is added to steel as a microalloying element, in amounts of a tenth of a per cent or less, to precipitate fine carbonitrides that pin the grain boundaries and strengthen the steel by precipitation and grain refinement at the same time. It is one of the cheapest ways to raise the strength of a structural steel, and it is why a modern rebar or a pipeline steel reaches its grade at a composition that is still weldable. But vanadium alone is only half the reaction: the precipitate that does the work is a carbonitride, and nitrogen is needed to form it. Adding vanadium as ferrovanadium to a steel with little nitrogen wastes a large part of it. Vanadium-nitrogen alloy supplies both together in a fixed ratio, which raises the vanadium yield substantially and means less vanadium is needed for the same strength - a direct saving in the most expensive addition in the ladle. The standard therefore specifies not just the vanadium content but the nitrogen content and the ratio between them, since that ratio is what the product is bought for, together with the carbon, the impurities, the density and the particle size, which determines how the alloy dissolves and how much of it is lost in the slag or the fume. The sampling and acceptance rules matter here because the material is expensive and traded on assay. Issued on 28 April 2020 and in force since 1 August 2020, it replaces GB/T 20567-2006.

This standard specifies the technical requirements, test methods, inspection rules, packaging, marking, storage, transportation and quality certification of vanadium-nitrogen alloys Books etc. This standard applies to vanadium-nitrogen alloys used in steelmaking and casting.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article Pieces. For undated references, the latest version (including all amendments) applies to this document.

GB/T 191 Packaging, Storage and Transportation Graphic Mark

GB/T 24583.1 Vanadium-nitrogen alloy-Determination of vanadium content-Ferrous ammonium sulfate titration method

GB/T 24583.2 Determination of nitrogen content of vanadium-nitrogen alloy inert gas fusion thermal conductivity method

GB/T 24583.3 Determination of nitrogen content of vanadium-nitrogen alloy Distillation-neutralization titration method

GB/T 24583.4 Determination of carbon content of vanadium-nitrogen alloy by infrared absorption method

GB/T 24583.5 Vanadium-nitrogen alloy-Determination of phosphorus content-Bismuth phosphorus molybdenum blue spectrophotometric method

GB/T 24583.6 Determination of sulfur content of vanadium-nitrogen alloy by infrared absorption method

GB/T 24583.7 Determination of oxygen content of vanadium-nitrogen alloy by infrared absorption method

GB/T 24583.8 Vanadium-nitrogen alloy determination of silicon, manganese, phosphorus, aluminum content inductively coupled plasma atomic emission spectrometry

3 Technical requirements

3.1 Brand and chemical composition Vanadium-nitrogen alloy is divided into three grades VN12, VN16 and VN19 according to different chemical compositions, and its chemical composition should meet the requirements of Table 1.

Note. The supplier can provide the test results of oxygen, aluminum, silicon, and manganese content after negotiation between the supplier and the buyer and indicated in the contract.

3.2 Apparent density The apparent density of VN12 and VN16 products should not be less than 3.0g/cm3, and the apparent density of VN19 products should not be small In 2.6g/cm3.

3.3 Granularity The particle size of the product should not be greater than 50mm, and the particle size of less than 10mm should not be greater than 5% of the total. According to user requirements, after negotiation between the supplier and the buyer and indicated in the contract, vanadium-nitrogen alloys with other particle size requirements can also be supplied.

5 Inspection rules

5.1 Vanadium-nitrogen alloys should be inspected and delivered in batches. Each batch consists of products of the same brand, and the mass of each batch should not exceed 3000kg.

5.2 When the inspection results do not meet the requirements, double samples can be taken from the same batch of products for re-inspection. If the re-inspection result still does not meet the requirements, it is judged This batch of products is unqualified.

6 Packaging, marking, storage, transportation and quality certificate

6.1 Packaging The product is packed in a moisture-proof bag, 5kg or 10kg per bag; then put the product in the moisture-proof bag into a packaging barrel or packaging bag and package it. 50kg or 100kg per barrel when packed, and 1000kg per bag when packed in bags. The moisture-proof bag is required to be complete and undamaged, and the packaging bag and packaging barrel are both Should be tightly sealed. Other packaging methods can also be used according to the contract.

6.2 Logo The product name and net content should be marked on the inner packaging of the moisture-proof bag. The outer packaging of the product should be marked with the name and address of the manufacturer, product name and Brand number, product standard number, production date, batch number, net content (for quantitative delivery), etc. The packaging, storage and transportation pictorial signs should meet the requirements of GB/T 191.

6.3 Storage Products should be stored in a ventilated, dry, non-corrosive gas environment warehouse.

6.4 Transportation During transportation, the product should be packed and handled carefully, and no heavy pressure and violent collisions should be allowed to avoid damage and deformation of the product packaging.

6.5 Quality Certificate Each batch of products that leave the factory should be accompanied by a quality certificate. The content of the certificate includes. the name and address of the manufacturer, the name and brand of the product, and the product Standard number, contract number, batch number, batch size (number of pieces and total quality) and product quality inspection results.