After visual inspection and metallographictest, analysis and discuss the welding zone cracking reasons for 6061 and A7003 aluminum alloy thin-walled tube after TIG (argon shielded arc) welding.
It was approved by metallographictest that the sound velocity measured by the instrument was more accurate. The instrument was easy for operation and could be used to realize automatic control.
The concept and grading method of the "martensitic grade" in the standard of "Metallographictest for Carburizing Auto Gear" were analyzed and discussed according to the experience and test results.