GB/T 13925-2025 Metallographic test method for high manganese cast steel English
1 Scope
This document specifies the metallographic sampling method and microstructure of high manganese cast steel, and the basis for evaluating the grade of carbide, grain size and nonmetallic inclusion.
This document is applicable to the metallographic test of water-toughened austenitic manganese steel castings specified in GB/T 5680, except for medium manganese steel ZG120Mn7Mo. Metallographic test for other water-toughened high manganese cast steel may be carried out with reference to this document.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 5611 Foundry terminology
GB/T 5680 Austenitic manganese steel castings
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 13298-2015 Inspection methods of microstructure for metals
GB/T 40805-2021 Steel castings - General technical delivery requirements
3 Terms and definitions
For the purpose of this document, the terms and definitions given in GB/T 5611 apply.
3.1
average diameter
average size of major axis and minor axis of a particle
Note: The major axis size refers to the maximum size of a particle, and the minor axis dimension refers to the maximum size perpendicular to the major axis direction.
4 Sampling method
4.1 Samples shall be cut from the casting or its attached casting test block or single casting test block, or directly observed by metallography. The specific sampling position of the casting or its attached casting test block shall be determined by both parties. The shape and size of a single casting test block shall meet the requirements of Figure 1 in GB/T 40805-2021. Unless otherwise agreed by the both parties, the supplier may choose one type of single casting test block. The metallographic specimen of the attached casting test block or single casting test block shall be made at least 6 mm away from the casting surface.
4.2 The samples shall be protected from thermal influence during cutting and preparation.
4.3 The sample size shall be less than 400 mm2 according to GB/T 13298-2015.
