MACROSCOPIC EXAMINATION
MACROETCH, GRAIN FLOW, SURFACE CONDITION & MORE
Zhejiang Guojian Testing Technology Co., Ltd (CCT) , located in China, provides a range of macroscopic examination services performed by their team of experienced metallurgical engineers. Macroscopic examination, also known as macro test or macro examination, involves the evaluation of a test sample's quality and consistency using low or no magnification. This technique can be used to assess various macrostructural features of metals, including grain flow, cracks, and porosity.
Zhejiang Guojian Testing Technology Co., Ltd (CCT) CAPABILITIES
· Macroetching (ASTM E340)
· Grain Flow
· Weld Qualification
· Surface Condition
· Surface Finish
· Digital Imaging
At Zhejiang Guojian Testing Technology Co., Ltd (CCT) , our metallurgical engineering team prepares the macro samples by performing cutting, grinding, polishing, and etching. Once prepared, the macroscopic examination is carried out, and the findings are documented using digital imaging. This allows customers to receive a visual image of their test report or a digital file that can be easily shared via email.
STANDARDS/SPECIFICATIONS
· ASME Sect. IX
· ASTM E340
· ASTM E381
Get in touch with us to discuss your materials and specific requirements for macroscopic examination. We offer macro examination services for specimens exposed to passivation, salt spray, case depth, and other testing. Additionally, we frequently perform macroscopic examination of welds, which can reveal internal discontinuities, weld profile, extent of penetration, and other properties that are important for weld procedure qualification or welder qualification.
THE TEST PROCESS
Preparing the test sample to specification is a crucial step before macroscopic examination can be carried out. It involves cutting, grinding, and polishing the sample. Often, etching is required after the sample has been prepared, which involves a chemical reaction on the surface of the sample to reveal its flow properties. The sample can be in the form of ingots, castings, plates, bars, sheets or finished products.
Macro examination can be carried out on the transverse or longitudinal cross-section of the test sample. The sample is viewed with the naked eye or at low magnification, usually not exceeding 10 times.
ASTM E340 specifies the macroetch test, which involves controlled surface etching of a metal or alloy sample to reveal its structure, such as grain flow lines and ingot patterns. These features are visible at low magnification and can provide insight into the material's manufacturing process, including the manner in which the metal flowed during forming.
