Terms Related to Ordering Metal Materials
1. Material name: The exact name of the material ordered. The names of some materials are easy to confuse. For example, general-purpose low-carbon steel wire and low-carbon knotted steel wire have similar names, but their quality, use, and price are different.
2. Variety: Different products such as material chemical composition, use, shape, production process, heat treatment, etc.
3. Specifications: The different sizes of the same product or the same model are usually expressed by the nominal size of the main part of the section.
4. Nominal size: The nominal size specified in the standard is also the ideal size expected in the production process.
5. Actual size: The actual size of the material in the production process.
6. Size deviation: the difference between the actual size and the nominal size. The size deviation allowed by the standard is called the allowable deviation. Referred to as deviation.
7. Accuracy grade: The grade according to the allowable size deviation in the standard. The higher the accuracy level, the smaller the allowable size deviation. When ordering metal materials, the required dimensional deviation or accuracy level should be stated.
8. Normal length: Also known as indefinite length, the delivery length of metal materials is required to be within the length range specified by the standard, and the length of a specific size is not required.
9. Cut-to-length length: Cut into a fixed-size length according to the order requirements (the length of the plate refers to the width and length). For example, the length is 5m, and the length of the delivered batch of materials is 5m.
10. Length of multiple ruler: Cut the length of the single ruler required by the buyer into integer multiples of length.
11. Short ruler: The length less than the lower limit of the indefinite length specified by the standard, but not less than the minimum length allowed. For example, hot-rolled high-quality round steel usually has a length of 2-6m, and the minimum allowable length is 1.5m. The length of 1.5-2m is a short rule. Metal materials delivered in the usual lengths are allowed to match a certain proportion of short lengths.
12. Technical conditions: The standards stipulate the various performance indicators and quality requirements that the product meets, such as grades, surface quality, physical properties, chemical properties, mechanical properties, process properties, internal organization, delivery status, etc. Sometimes it also includes some performance indicators for reference. Grade is the primary content in the technical conditions. Materials of the same grade may have different guarantee conditions, delivery status, use processing types, quality levels, etc.
13. Brand: It is used to identify product name, symbol, code or their combination. The steel grade is called the steel grade, which is the name given to each specific steel. In the past standards, names expressed in Chinese characters were often referred to as brand names, and those expressed in Chinese pinyin letters and elements were called codes. In the current standard, Chinese characters are no longer used to represent brand names. Therefore, the steel grade and grade are merged into one.
14. Material: Usually refers to the steel grade and quality of the steel. In actual work, it generally refers to the steel grade.
15. Assurance conditions: According to the metal material standards, the manufacturer should conduct inspections and ensure that the inspection results meet the specified quality indicators.
16. Delivery status: The final plastic deformation processing method or final processing status of the metal spring material. The final plastic deformation processing method can also be understood as the state of delivery without heat treatment, such as hot rolling (forging), cold drawing (rolling), etc.; the final heat treatment state includes normalizing, annealing, high temperature tempering, quenching and tempering and solid solution Processing etc. The delivery status directly affects the performance and use of the material. The correct selection of the delivery status is of great significance to the further processing and processing of the user, ensuring product quality, and reducing costs. When ordering materials, it must be in the manifest, contract and other documents Please indicate what delivery status is required.
17. Hot-rolled (forged) state: The state where the metal material is no longer subjected to special heat treatment after hot-rolled or hot-forged, and delivered directly after cooling. The termination temperature of hot rolling (forging) is generally 800 to 900°C, and then it is generally cooled in air, so the state of hot rolling (forging) corresponds to normalizing treatment. The metal material delivered in the hot rolled (forged) state has a certain degree of corrosion resistance because the surface is covered with a layer of oxide film. The storage, transportation and storage requirements are not as strict as the cold drawn (rolled) delivery materials, such as large, Medium-shaped steel and medium-thick steel plates can be stored in the open yard or after being covered.
18. Cold drawn (rolled) state: the state where metal materials are delivered directly after cold drawing or cold rolling without special heat treatment. Compared with the hot-rolled (forged) state, the cold-drawn (rolled) state of metal materials has high dimensional accuracy, good surface quality, low surface roughness, and higher mechanical properties. However, it is prone to corrosion or rust, and its packaging, storage and transportation have strict requirements. It must be kept in a warehouse, and attention should be paid to the temperature and humidity control in the warehouse.
19. Annealing (simmering) state: The state of the metal material after annealing and heat treatment before leaving the factory. The purpose of annealing is mainly to eliminate and improve the organizational defects and internal stress left by the previous process, and to prepare the organization and performance for the subsequent process.
20. Normalizing state: The state of the metal material after being normalized and heat treated before leaving the factory. Compared with hot rolling (forging), because of its stricter temperature control, the structure and properties of the metal are more uniform; compared with annealing, because the normalizing cooling rate is faster, the grains are refined and the mechanical properties are higher , And can eliminate some structural defects of steel.
21. High-temperature tempering state: The state of the metal material after high-temperature tempering heat treatment before leaving the factory. High temperature tempering has a higher tempering temperature, which is beneficial to completely eliminate internal stress and improve the plasticity and toughness of the metal.
22. Solution treatment state: The state of the metal material after solution heat treatment before leaving the factory. Solution treatment is mainly suitable for austenitic stainless steel to obtain single-phase austenitic structure, improve the plasticity and toughness of steel, and create conditions for further cold working; it can also prepare the structure for further precipitation hardening of stainless steel or aging treatment of non-ferrous metals .
23. Free processing state: In the molding process, the mechanical properties of the product without special requirements for work hardening or heat treatment conditions are not guaranteed.
24. Work-hardened state: the state in which metal materials are delivered directly without special heat treatment after cold working. It is suitable for non-ferrous metal products whose strength is increased by work hardening. After work hardening, the product can undergo (or not) additional heat treatment to reduce the strength.
25. Quenched state: The state of the metal material after quenching and heat treatment before leaving the factory. For non-ferrous metals, the main purpose of quenching is to obtain a single-phase structure and prepare the structure for further cold working or aging treatment.
26. Quenching-natural aging state: metal materials are quenched-natural aging heat treatment state before leaving the factory.
27. Quenching-artificial aging state: the state of the metal material after quenching-artificial aging heat treatment before leaving the factory.
28. Marks: In order to facilitate the management of metal spring materials, avoid confusion and prevent accidents from use, the brand, batch number, status, specifications, and manufacturer code are marked on the material or packaging, collectively referred to as the mark. The marking methods mainly include coloring, printing, and listing.
29. Quality certificate: the certification materials attached to each batch of delivered products by the manufacturer. The content is in accordance with the relevant standards and the provisions of the order contract, and generally includes the material name, brand, specification, quality level, inspection results of all inspection items specified in the contract and standards, contract number, standard number, inspection lot number, number of pieces delivered, weight, etc. . The quality certificate is the supplier’s confirmation and guarantee of the inspection results of the batch of products, and it is also the basis for the buyer to perform re-inspection and use. It is an important technical document in purchase and sales activities. Not only should the manufacturer provide a quality certificate when leaving the factory, but also must issue a quality certificate or its copy along with the materials when selling or sending out materials.