Low Times Metallographic Test

Testing range:

Butt joint with full penetration、T-joint with full penetration、Branch connection with full penetration.

Welding of metallic materials forming process, the regional welded joint is subjected to different thermal cycling, which also obtained tissue is very different, leading to changes in mechanical properties. Welded joints for metallurgical analysis, is an important means of joint performance analysis and identification, which in scientific research and production has been widely used. Welding joint metallurgical analysis includes both macroscopic and microscopic analysis.

Macro photo of welded joint

Microscopic analysis by means of an optical microscope or an electron microscope （＞100×）to analyze the crystalline form of the weld, the weld heat affected zone of the organization, as well as the distribution of microscopic defects.

Welding joint analysis of pipeline

Pipeline is mainly used for welding refers to transportation of oil, natural gas, large diameter steel pipe with a heavy plate or hot-rolled coil. Modern pipeline belonging to low- or ultra-low carbon micro-alloyed steel, is high-tech and high value-added products.

Due to lowor ultra-low carbon micro-alloyed pipeline steel, its welded joint organizational change is still within the scope of the previously discussed, there are also fusion zone, overheated zone, normalizing zone and incomplete recrystallization region.

Fusion zone

Overheated zone

Normalized zone

Incomplete recrystallization zone