Metal Forging Transport Services

The mechanical property advantage of forgings over castings and bar-machined components comes from the controlled grain flow that the forging process produces. High-impact events during transport that introduce concentrated stress at forging surfaces can initiate microstructural damage at the impact location that affects the local mechanical properties in ways that are not detectable by visual inspection. For aerospace and safety-critical forgings where mechanical property integrity is verified by certification rather than by individual part testing, transport-induced microstructural damage represents a quality compromise that the certification cannot account for.

Closed-die forgings have a die parting line where the upper and lower dies meet during forging, and some forgings arrive from the forge shop with residual flash at the parting line that will be removed during machining. The parting line area and any flash extensions are stress concentration locations that are more susceptible to impact cracking than the forging body proper. Blocking and handling that concentrates load at parting line locations, or that allows forging-to-forging contact at parting line areas, creates surface cracking that propagates into the forging body and may not be detected until non-destructive testing during the machining inspection process.

Many high-performance forgings undergo heat treatment after forging to achieve the mechanical property levels specified for their application. The heat treatment process can leave residual stress in the forging that makes it dimensionally sensitive to mechanical disturbance during transport. A forging with significant residual stress from heat treatment that is improperly blocked on the trailer and subjected to vibration during a long haul can develop stress relief distortion that changes its dimensional relationship between machined surfaces in ways that affect subsequent machining operations.

Aerospace forgings in titanium, aluminum, and nickel alloys are subject to material and process certification requirements that trace the forging from the ingot heat through every processing step including the forging process itself, heat treatment, and any non-destructive testing performed before shipment. Those certifications accompany the forging through every supply chain transfer and must arrive with the forging at the machining facility for the incoming receiving inspection. A certification package that is lost, damaged, or incomplete during transport creates an airworthiness compliance issue that the machining facility cannot resolve without contacting the forge shop for replacement documentation.

Large industrial and structural forgings for heavy equipment, offshore oil and gas applications, and power generation use can weigh tens of thousands of pounds per piece. Handling those forgings requires crane equipment at both the forge shop and the receiving facility that is sized for the forging weight and rigged correctly for the forging geometry. A receiving facility whose crane is undersized for the forging weight cannot complete the offload without additional equipment. Confirming crane capacity and rigging requirements at both facilities before dispatch prevents the standby situations that develop when equipment specifications are assumed rather than verified.

Forgings are produced with machining stock on all surfaces that will be machined to final dimensions. That stock represents the material available for the machining operation to work with in bringing the forging to its final dimensional requirements. Surface damage during transport that removes material from machined surface locations reduces the available machining stock below the minimum required for a clean finish cut, causing the machined surface to show forging skin in the finished machined area. For tight-tolerance machined surfaces where forging skin in the finished surface is a rejection criterion, stock loss from transport damage creates a machining failure before the machining operation begins.