【国外标准】 Standard Specification for Steel Bars, Alloy, Standard Grades

This specification covers hot-wrought alloy steel bars. The steel shall be made by one or more of the following primary processes: open-hearth, basic-oxygen, or electric-furnace. The primary melting may incorporate separate degassing or refining and may be followed by secondary melting using electro-slag remelting or vacuum arc remelting. Where secondary remelting is employed, the heat shall be defined as all of the cast product remelted from a single primary heat. The steel shall be furnished as strand cast or ingot cast. Immediately after hot forming, the bars shall be allowed to cool to a temperature below the critical range under suitable conditions to prevent imperfections caused by too rapid cooling. The bars shall be free of pipe, cracks, and flakes. Within the limits of good manufacturing and inspection practices, the bars shall be free of injurious seams, laps, segregation, or other imperfections which are due to their nature, degree, or extent, will interfere with the use of the material in machining or fabrication of suitable parts.1.1 This specification covers hot-wrought alloy steel bars. Bar applications include forging, heat treating, cold drawing, machining and many structural components (Note 1).NOTE 1: A guide for the selection of steel bars is contained in Practice A400.1.2 The bars shall be furnished in the grades specified in Table 1. Sections and sizes of bar steel available are covered in Specification A29/A29M. Hot-wrought alloy steel bars are produced in cut lengths and coils; the manufacturer should be consulted regarding sections and sizes available in coils, produced to a chemical composition.1.3 Some applications may require superior surface quality, or special chemical restrictions, metallurgical characteristics, heat treatment, or surface finishes which the purchaser may obtain by designating one or more of the available Supplementary Requirements.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.