Analysis of the Function and Machining Process of Marine Connecting Rods

The connecting rod in a ship connects the piston and crankshaft, converting the linear motion of the piston into the rotational motion of the crankshaft, thereby outputting power. It bears huge alternating impact loads, tensile and compressive stresses, and bending stresses, so its strength, toughness, and fatigue performance are extremely high.

Its machining process is complex and precise. First, high-quality alloy steel is used for die forging to obtain dense fiber streamlines. The main processing steps include: rough and fine boring of the big end hole and the small end hole to ensure the parallelism and center distance accuracy of the hole system; high-precision milling and grinding of the joint surface; drilling and reaming of the bolt holes; and overall stress relief treatment and surface polishing. Finally, strict non-destructive testing such as magnetic particle inspection is required to ensure that there are no internal defects and to ensure reliability and long life under harsh working conditions.