Application of Q345B Steel Tube to Manufacture of Hydraulic Cylinder Casing for Construction Machinery Service

Described here is how relevant testing activities are made to verify the substitution of the Q345B alloy steel tube for the 45 steel tube to manufacture the hydraulic cylinder casing for the crane truck. With relevant theoretic analysis and tests, the Q345B steel is compared with the 45 steel in terms of mechanical property and weldability. And the former is also used to produce casings in lots which then, are mounted to crane trucks for the work condition test. The verification result demonstrates that the material can fully meet the requirements for crane truck service. Using the Q345B alloy steel instead of the 45 steel to make the hydraulic cylinder casing of the crane truck’s supporting leg will bring about such advantages as reduction of the cylinder’s welding defect rate by over 50%, increase of the elongation after fracture, assurance of the casing’s toughness, and less risk of its brittle fracture so as to get the safety reliability of the hydraulic cylinder enhanced significantly.