Excavator Arm Material Selection and Machining Process Analysis

The material selection of the excavator arm is the primary factor determining its service life and operational reliability. Because the boom needs to withstand enormous bending, torsional, and impact loads during operation, and frequently rubs against materials such as sand and soil, the material must possess extremely high strength, excellent toughness, and outstanding wear resistance. The industry generally chooses high-yield-strength low-alloy steel as the base material. This type of steel, through the addition of specific alloying elements, improves strength while ensuring good plasticity and low-temperature impact toughness, effectively preventing brittle fracture caused by overload or accidental impact.

After determining the core material, a systematic and precise machining process is the key to transforming it into a qualified product. The process begins with precise blanking based on a three-dimensional model, usually using CNC plasma or laser cutting to ensure the accuracy of subsequent assembly. For arm bodies requiring complex curved surfaces, large presses are used for hot pressing. Subsequently, each component is positioned using high-precision tooling fixtures, and the main welds are completed by an automated welding system. Among these, the welding process is crucial, requiring strict control of heat input and interpass temperature, and may be accompanied by preheating and post-heating measures to eliminate welding stress, prevent crack generation, and ensure that the weld strength matches the base material. After welding, the overall structure often needs to undergo stress-relief annealing to stabilize dimensions and further improve structural stability. Finally, the critical pin shaft holes are precision bored or milled to ensure their position, dimensional accuracy, and surface finish, thereby ensuring the flexibility and stability of the entire boom mechanism.