The recommended national standard GB/T 16555-2025 "Chemical Analysis Methods for Carbon, Silicon Carbide, and Nitride Refractory Materials", drafted and revised by Sinosteel Luoyang Institute of Refractories Research Co., Ltd., was released on August 29, 2025 and will be implemented on March 1, 2026.

The release status of each version of this standard：

The first edition (1996 edition) was drafted and approved by the Chemical Analysis Department of the Quality Inspection Center of Luoyang Refractory Materials Research Institute, based on the German standard DIN51075 "Testing Methods for Silicon Carbide Chemical Analysis of Ceramic Materials" (1982 edition). After systematic and comprehensive testing, data accumulation, and determination of parameter conditions, it was first published in 1996;

The second edition (2008 edition) is based on the integration of GB/T 16555.1~16555.6-1996, GB/T 13245-1991, and GB/T 13246-1991 standards, adding clauses such as items and methods, changing the standard name, and expanding the scope of application;

The third edition (2017 edition) added a detection item for total oxygen content, defined the scope of some detection items, and supplemented the reference to inductively coupled plasma emission spectroscopy method.

The main differences between this revision and the previous version are as follows:

a）Changed the element 'scope' to include the determination of hafnium oxide and yttrium oxide; Change the range of F.Si to ≥ 0.1% and the range of F.Al to ≥ 0.1% in Table 1; Change the range of TiO2 to ≤ 20%; Change the range of MnO to ≤ 5%; Add analysis items ZrO2, HfO2, and Y2O3. And make provisions for the allowable deviation of its adjustment parts (see Table 1 in Chapter 1 and Table 2 in Chapter 6, Chapter 1 and Chapter 6 of the 2017 edition);

b）Added normative reference document "GB/T 6682 Specification and Test Methods for Water Used in Analytical Laboratories" and modified the reference document name "GB/T 17617 Sampling Inspection Rules for Refractory Raw Materials" (see Chapter 2, 2017 edition, Chapter 2);

c）Added pH meter in "Instruments and Equipment" (see Chapter 4 of 4.11, 2017 edition);

d）The particle size requirement for sample breakage in "Sample Preparation" has been changed to allow it to pass through the corresponding standard sieve (see 5.2 in the 2017 version);

e）Changed the provisions for pure water in the "General Principles" element (see Chapter 6, 2017 edition of Chapter 6);

f）Added the element of "Determination of 850 ℃ ignition loss by box type high-temperature furnace oxidation method" test conditions, and added the detection of 1050 ℃ ignition loss (see 8.2.2, 9.2 of the 2017 version)

g）Change the reaction equation from Si+OH -+H2O=SiO32-+2H2 ↑ to Si+2NaOH+H2O=Na2SiO3+2H2 ↑; Add "The saturated vapor pressure of pure water can be found in Appendix B, Table B.1" in the principle (see Section 14.1.1, 15.1.1 of the 2017 edition);

h）The volume of the measuring tube and reference tube in the element "Reagents and Materials" has been changed to 25mL or 50mL or an appropriate volume, with a reading accuracy of 0.1 mL (see Section 14.1.2.10, 2017 edition 15.1.2.10);

i）Modify and explain the materials in the "principle" of the element that are not applicable to this method, stating that "this method is applicable to samples that do not contain free magnesium, free iron, etc. that can react with hydrochloric acid to produce gas" (see Section 15.1.1, 6.1.1 of the 2017 edition);

j）Add the determination of hafnium oxide and yttrium oxide to the determination of oxide content (see Chapter 17, Chapter 18 of the 2017 edition).