METALLOGRAPHIC TESTS
Metallography is a science that examines the internal structure of metallic materials by using optical and electron microscopy methods. This method is performed for detecting microstructure of metals which are affected by composition, hot and cold working, machining and welding processes. In addition, the corrosional effects on microstructure, metallic coating thickness and uniformity, effects of carburization and nitriding processes on microstructure can be analyzed by this method. Metallography is a very effective method at quality control studies and failure analysis.

Macro Analysis
Macro Analysis is implemented by ASTM E340 standard. Macro Analysis is a method that etched a specimen and evaluated macro structure of materials at low magnifications. 
This technique is especially used for steel products and welded materials. Macro analysis is frequently performed on a polished and etched welded material. Defects are observed such as slag, porosity, poor penetration, lack of sidewall fusion, poor weld profile by macro examination. (ASTM E340 - 00(2006): Standard Test Method for Macroetching Metals and Alloys).

Micro Analysis
Micro Analysis is performed by ASTM E407 standard. Micro-analysis technique is applied to detailed information about the internal structure of materials. 
The third phase precipitation, excessive grain growth, grain orientations can be detected by this technique. In addition, the phase counting and grain size determination is closely related to this method. For this analysis, the sample is cut the main pieces, is taken into a mold bakelite or resin, polished, etched and microstructure are analyzed its microstructure. (ASTM E407 - 07e1: Standard Practice for Microetching Metals and Alloys).

Weld Defects Analysis
The most basic form of metallographic weld examination is based on visually examined porosity, lack of sidewall fusion, lack of penetration, etc. In addition, analysis of the third phase, the grain size control, observations such as the inclusion of this determination is within the scope of the test.

Case Depth Analysis
Case Depth Analysis is performed by ASTM B931-09 standard. Coating process is a technique to form a hard surface layer which is harder than the base material on the surface of a metallic material. Carburization, nitriding, carbonitriding, induction hardening or flame hardening are basic surface hardening operation.  coating quality, depth and the chemical structure can be examined with metallographic techniques. (ASTM B931–09: Standard Test Method for Metallographically Estimating the Observed Case Depth of Ferrous Powder Metallurgy (P/M) Parts).

Carburization Measurement Analysis
Decarburization Measurement Analysisis performed by ASTM E1107 standard. This method is applied to determine the microstructural changes on the surface of steel materials by the effect of carburization, the hardness changes and the carbon content.  For the measurement of the depth, a region must be selected that microstructure of the material, hardness and carbon content is uniform. Surface losses of heat treated materials in carbon content can also be determined by this process. (ASTM E1107–10:Standard Test Method for Measuring the Throughput of Resource-Recovery Unit Operations).

Coating / Plating Analysis
Coating/Plating Analysis is performed by ASTM B487, ASTM B748 standards. Coating aplication is applied to protect the main surface. The thickness of the coating is very effective in the performance of the protection process. For determination of coating thickness, sample is cut, polished, etched and examined microscopically. If the coating thickness is too thin may need an electron microscope.              (ASTM B487 - 85(2007):Standard Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of a Cross Section, ASTM B748 - 90(2010):Standard Test Method for Measurement of Thickness of Metallic Coatings by Measurement of Cross Section with a Scanning Electron Microscope).

Grain Size Determination
Grain Size Determination is performed by ASTM E112 standard. Grain size affects mechanical properties of materials such as excessive grain growth reduces strength of materials. Therefore alloying is added for refinement of grain size and distribution of grain size. Grain size examination is performed on the polished and etched specimen at magnification about 100X. (ASTM E112 – 10: Standard Test Methods for Determining Average Grain Size).

Graphite Distribution Analysis
Graphite Distribution Analysis is performed by ASTM A247, ASTM E3, ASTM E407 standards. This metallographic analysis is performed for determination structure of graphite in ductile iron. Graphites significantly attribute strength of materials but if graphite forms is flakes that is not true. Iron castings samples are cut, polished and etched. Impact resistance and strength can be preticted by using graphite microstructure. (ASTM A247 – 10: Standard Test Method for Evaluating the Microstructure of Graphite in Iron Castings, ASTM E3 – 11: Standard Guide for Preparation of Metallographic Specimens, ASTM E407 - 07e1: Standard Practice for Microetching Metals and Alloys).