Steel examination by sulphur print (Baumann method)
1 Scope
This standard specifies the principle and purpose, specimen preparation, materials and reagents, test procedures, test safety, examination results and test report of steel examination by sulphur print (Baumann method).
This standard is applicable to steel with sulphur content greater than 0.0050%, and may also be used for cast iron.
2 Normative references
The following referenced documents are indispensable for the application 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 8978-1996 Integrated wastewater discharge standard
3 Principle and purpose
3.1 The sulphur print test is a qualitative test, thus it is not appropriate to estimate the sulphur content of steel only with the results of the sulphur print test.
3.2 The purpose of the sulphur print examination is to determine the distribution location of sulfide inclusions in steel by prints on printing paper pre-soaked in an acid solution.
3.3 Sulphur-enriched regions appear as a result of the blackening of the emulsion's silver halide to silver sulfide due to the precipitation of hydrogen sulfide.
3.4 Through the analysis of the distribution and amount of sulfide determined by this method, the purity degree of the steel in the examined part may be estimated. For example, sulphur prints may show inhomogeneities in chemical composition (such as segregation in free-cutting steels) and defects in certain features (such as cracks and pores). In addition, the sulphur print may be used to distinguish between rimming steel and killed steel, and may also be used to identify the parts that need to be tested (such as mechanical property tests) or sampled for analysis.
3.5 According to the test, the degree of blackening of the emulsion is not always proportional to the sulphur content of the steel. Certain factors also affect the results of corrosion.
Foreword i
1 Scope
2 Normative references
3 Principle and purpose
4 Sampling and preparation
5 Materials and reagents
6 Test procedures
7 Test safety
8 Examination results
9 Test report
Annex A (Informative) Schematic diagram for sulphur print images of steel
Steel examination by sulphur print (Baumann method)
1 Scope
This standard specifies the principle and purpose, specimen preparation, materials and reagents, test procedures, test safety, examination results and test report of steel examination by sulphur print (Baumann method).
This standard is applicable to steel with sulphur content greater than 0.0050%, and may also be used for cast iron.
2 Normative references
The following referenced documents are indispensable for the application 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 8978-1996 Integrated wastewater discharge standard
3 Principle and purpose
3.1 The sulphur print test is a qualitative test, thus it is not appropriate to estimate the sulphur content of steel only with the results of the sulphur print test.
3.2 The purpose of the sulphur print examination is to determine the distribution location of sulfide inclusions in steel by prints on printing paper pre-soaked in an acid solution.
3.3 Sulphur-enriched regions appear as a result of the blackening of the emulsion's silver halide to silver sulfide due to the precipitation of hydrogen sulfide.
3.4 Through the analysis of the distribution and amount of sulfide determined by this method, the purity degree of the steel in the examined part may be estimated. For example, sulphur prints may show inhomogeneities in chemical composition (such as segregation in free-cutting steels) and defects in certain features (such as cracks and pores). In addition, the sulphur print may be used to distinguish between rimming steel and killed steel, and may also be used to identify the parts that need to be tested (such as mechanical property tests) or sampled for analysis.
3.5 According to the test, the degree of blackening of the emulsion is not always proportional to the sulphur content of the steel. Certain factors also affect the results of corrosion.
Contents of GB/T 4236-2016
Foreword i
1 Scope
2 Normative references
3 Principle and purpose
4 Sampling and preparation
5 Materials and reagents
6 Test procedures
7 Test safety
8 Examination results
9 Test report
Annex A (Informative) Schematic diagram for sulphur print images of steel