This standard specifies the tolerances on dimensions, shape and mass for semi-finished products intended to undergo hot forming by forging, i.e. blooms, slabs and billets made of:
——General purpose steels, in accordance with EN 10250-1~4 (see Bibliographies)
——Steels for pressure purposes, in accordance with EN 10222-1~5 (see Bibliographies)
It does not cover semi-finished products intended for open die forging which are covered by EN 10243-1 (see Bibliographies).
2 Normative References
The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding amending error in the text), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest edition of these documents is applicable. For undated references, the latest edition of the normative document is applicable to this standard.
EN 10079:1992 Definition of Steel Products
3 Terms and Definitions
For the purposes of this standard, the terms and definitions given in EN 10079:1992 apply.
4 Appearance and Soundness
4.1 General
The semi-finished products shall be in good condition and free from defects such as segregation, cracks, laminations and other imperfections that preclude their intended use.
4.2 Removal of surface defects
Surface defects shall be removed by dressing in order to conform to 4.1. Dressing may be carried out by chipping and/or grinding or by any suitable method providing:
——The resulting depression for a single face shall not exceed 2% of the nominal size or 3 mm, whichever is greater;
——In the case of removal of defects the same cross section, the residual dimensions shall remain within the specified tolerances;
——In order to ensure adequate forging, the width of the removed area shall be ≥ 6 times of its depth and the resulting depression shall not undercut the surface.
GB/T 20911-2007 The following standards are cited：
