In the production process of welded steel pipe, quality inspection is a very importance of foundation link. In general, pipe manufacturer will use optical microscope to test weld seam. Optical microscope is light waves to deal with visible and near-visible, bunching the beam to irradiate on the object, the imaging falls on the human retina, photosensitive film or other recording system, breaking the limitations of human physiology, the visual extension to The human eye can not tell the microscopic world. It is the most important optical precision instrument used to observe, record and study the fine structure of the object being examined.
High-frequency welded steel pipe is using the welding method to effectively connect the metal material. When pipe manufacturers produce high-frequency welded steel pipe (such as ERW steel pipe, LSAW steel pipe, spiral welded pipe), many factors in the welding process directly affect the weld metal and heat affected area of the macrostructure and microstructure, welding defects and welding joints performance. Therefore, the study of the weld area of the organization, welding defects and joint performance, as soon as possible to find and solve the welding quality problems, must use the macro test analysis and microstructure test.
Macro-inspection, including the appearance of quality inspection and low-power tissue analysis, you can understand the welding structure and welding products, the main appearance, resulting in defects of the nature of the site and its overall relationship with the welding structure and so on. It is necessary to assess and control the quality of the pipe and to prevent major accidents. This requires a microscopic examination of a stereomicroscope.
Microstructural inspection is the process of analyzing and testing the microstructure of weld metal, the characteristics of fusion structure, and the characteristics of weld heat affected zone. To understand the state of microstructure, to ensure the quality of welded pipe, you need high-power microscope observation, recording microstructure characteristics.