BOOM/ARM MEMBER FOR CONSTRUCTION MACHINE, HAVING HIGH WELDED PORTION FATIGUE STRENGTH, AND METHOD OF IMPROVING THE FATIGUE STRENGTH

摘要

The present invention has excellent fatigue strength of the weld boom of construction machinery and arm members and the fatigue strength improvement methods to provide a boom and arm member of a construction machine and the boom and arm member of the full penetration of the weld zone fatigue strength of a boom of a construction machine characterized in that it has excellent blow Zidane common with the portion of the welded portion and the arm member and the fatigue how to improve the strength . Preferably, the residual stress of the bottom surface of the impact is common with the residual compressive stress is at least 10 .