In the field of hydraulic machinery manufacturing, the quality of cylinder forgings, as key components for system pressure loading, directly affects the safety of equipment operation and service life. A hydraulic machinery factory in Jinghai, Tianjin, has long faced process challenges such as insufficient material strength, uneven machining allowances, and substandard internal microstructure density during forging, resulting in low product pass rates and high rework costs.

Customer pain point analysis

The original supplier of the factory had the following issues with the cylinder forgings provided by the factory:

• Material selection standards are too low, causing microcracks in the cylinder under high pressure, raising leakage risks;
• Unstable control of forging ratio, uneven distribution of internal flow lines of forgings, and affecting fatigue life;
• Excessive machining allowance extends subsequent machining cycles and reduces overall production efficiency;
• Some batches of forgings have internal looseness or inclusions, with an ultrasonic flaw detection pass rate of less than 70%.

Jianing forging solutions

To address these pain points, the Jianing forging team has carried out specialized technical breakthroughs and provided customers with customized cylindrical forging products:

• Preferred material system: uses low-alloy relatively high strength steel that meets GB/T 1591 standards, helping to match tensile strength and toughness under high-pressure conditions;
• Optimizing forging processes: Through multi-directional forging and temperature-controlled forging technologies, internal grain refinement and streamlines are reasonably distributed along the axial direction of the cylinder, improving fatigue resistance;
• Accurate control of allowance: Reserve uniform single-side machining allowance based on the final cylinder size (controlled at 3~5mm), reducing machining time;
• Full-process non-destructive testing: 1. Ultrasonic flaw detection (compliant with NB/T 47013.3 standard) combined with magnetic particle inspection helps prevent internal defects beyond standard in forgings, raising the first-pass rate for flaw detection to over 95%.

Project Outcomes

After adopting the cylinder forgings provided by Jianing Forging, the first-pass pass rate for the hydraulic machinery factory increased from 68% to 94%, the machining cycle for single parts was shortened by about 25%, and overall manufacturing costs dropped by 12%. At the same time, the forgings showed no leakage or deformation during subsequent hydraulic tests, significantly improving the operational stability of the equipment.