Relationship between the chemical composition of steel is steel quality and end-use performance of one of the most important factors, and preparation of steel and heat treatment based on the final product. Therefore, the technical requirement of steel standard parts, often provided steel for first grade (grade) and its chemical composition, and in table format included in the standard, is the manufacturer and customer acceptance an important basis of chemical composition of steel and steel products.
① the smelting of steel components
General chemical composition refers to the melting of components specified in the standard. It refers to the finished steel, pouring the chemical constituents of the medium-term. So that it is representative, and which represents the average composition of the furnace or tank, provided in the standard methods for sampling, will be cast into small ingots of molten steel in mold, in their taking or planing on drilling and sampling, and prescribed standard methods (GB/T223) analysis, which must conform to the standards of chemical composition and basis for customer acceptance.
Composition and analysis component, is in accordance with the regulations on the finished steel (GB/T222) drill or dig chip sampling, and complying with the provisions of the standard method (GB/T223) for analysis of chemical composition. After the crystallization and deformation of steel, due to uneven distribution of alloying elements in steel (segregation), thus allowing composition and standard component range (melting component) between warp and deviations shall conform to the provisions of GB/T222.
Steel composition is primarily intended for use or used by quality inspection department quality, manufacturers generally do not do analysis of the finished product (except as required by users), but should ensure that the analysis of the finished product meeting the prescribed standards.
③ arbitration analyses
Due to two a laboratory analysis same samples of results has significantly difference and beyond two a laboratory of allows analysis errors, or production enterprise and using sector, and needed party and for party on same samples or same batch steel of finished analysis has differences views Shi, can by third party has rich analysis experience of authority units (as China Steel Research total hospital or has inspection qualification of test sector) for again analysis, that said of that arbitration analysis. Arbitration analysis shall be final judgment based on the results.