This technical information has been contributed by
The Forging Industry Association

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MAKING THE MOST OF FORGING BENEFITS:
FORGING COMPARISONS

Compare Forging to Casting
Stronger Casting cannot obtain the strengthening effects of hot and cold working. Forging surpasses casting in predictable strength properties--producing superior strength that is assured, part to part.
Defects refined in preworking A casting has neither grain flow nor directional strength and the process cannot prevent formation of certain metallurgical defects. Preworking forge stock produces a grain flow oriented in directions requiring maximum strength. Dendritic structures, alloy segregations and like imperfections are refined in forging.
More reliable, less costly Casting defects occur in a variety of forms. Because hot working refines grain pattern and imparts high strength, ductility and resistance properties, forged products are more reliable. And they are manufactured without the added costs for tighter process controls and inspection that are required for casting.
Better response to heat treatment Castings require close control of melting and cooling processes because alloy segregation may occur. This results in non-uniform heat-treatment response that can affect straightness of finished parts. Forgings respond more predictably to heat treatment and offer better dimensional stability.
Flexible, cost-effective production adapts to demand Some castings, such as special performance castings, require expensive materials and process controls, and longer lead times. Open-die and ring rolling are examples of forging processes that adapt to various production run lengths and enable shortened lead times.



Compare Forging to Powder Metallurgy (P/M)
Stronger Low standard mechanical properties (e.g. tensile strength) are typical of P/M parts. The grain flow of a forging ensures strength at critical stress points.
Higher integrity Costly part-density modification or infiltration is required to prevent P/M defects. Both processes add costs. The grain refinement of forged parts assures metal soundness and absence of defects.
Fewer secondary operations required Special P/M shapes, threads and holes and precision tolerances may require extensive machining. Secondary forging operations can often be reduced to finish machining, hole drilling and other simple steps. The inherent soundness of forgings leads to consistent, excellent machined surface finishes.
Design flexibility P/M shapes are limited to those that can be ejected in the pressing direction. Forging allows part designs that are not restricted to shapes in this direction.
More cost-effective Long production runs are often required to recoup initial P/M tooling investment. New P/M parts require long lead times. Forging can respond quickly to changes in product demand and remain cost effective once die tooling is available at the forge.
Broad supplier base P/M supplier base is limited. The comparatively larger number of qualified forgers ensures best possible service.



Compare Forging to Reinforced Plastics and Composites (RP/C)
Less costly materials High costs are incurred with advanced composite materials like graphite, aramid, S-glass and less common matrix resins. Forging materials are readily available and comparatively inexpensive.
Greater productivity New advanced-composite part designs may often require long lead times and substantial development costs. The high production rates possible in forging cannot yet be achieved in reinforced plastics and composites.
Established documentation RP/C physical property data are scarce and data from material suppliers lack consistency. Even advanced aerospace forgings are established products with well documented physical, mechanical and performance data.
Broader service temperature range RP/C service temperatures are limited and effects of temperature are often complex. Forgings maintain performance over a wider temperature range.
More reliable service performance Deterioration and unpredictable service performance can result from damage to continuous, reinforcing RP/C fibers. Forging materials outperform composites in almost all physical and mechanical property areas, especially in impact resistance and compression strength.



Compare Forging to Weldments/Fabrications
Production economies, material savings Welded fabrications are more costly in high volume production runs. In fact, fabricated parts are a traditional source of forging conversions as production volume increases. Initial tooling costs for forging can be absorbed by production volume and material savings and forging's intrinsic production economies--lower labor costs, scrap and rework reductions and reduced inspection costs.
Stronger Welded structures are not usually free of porosity. Any strength benefit gained from welding or fastening standard rolled products can be lost by poor welding or joining practice. The grain orientation achieved in forging makes stronger parts.
Flexible, cost-effective designs A multiple-component welded assembly cannot match the cost savings gained from a properly designed, one-piece forging. Such part consolidations can result in considerable cost savings.
More consistent, better metallurgical properties Selective heating and non-uniform cooling that occur in welding can yield such undesirable metallurgical properties as inconsistent grain structure. In use, a welded seam may act as a metallurgical notch that can lead to part failure. Forgings have no internal voids that cause unexpected failure under stress or impact.
Cost-effective inspections Weldments require costly inspection procedures, especially for highly stressed components. Forgings do not.
Simplified production Welding and mechanical fastening require careful selection of joining materials, fastening types and sizes; and close monitoring of tightening practice--both of which increase production costs. Forging simplifies production and ensures better quality and consistency--part after part.



Compare Forging to Machined Steel Bar/Plate
Broader size range of desired material grades Sizes and shapes of products made from steel bar and plate are limited to the dimensions in which these materials are supplied. Often, forging may be the only metalworking process available with certain grades in desired sizes. Forgings can be economically produced in a wide range of sizes--from parts whose largest dimension is less than 1 in. to parts weighing more than 450,000 lbs.
Grain oriented to shape for greater strength Machined bar and plate may be more susceptible to fatigue and stress corrosion because machining cuts material grain pattern. In most cases, forging yields a grain structure oriented to the part shape, resulting in optimum strength, ductility and resistance to impact and fatigue.
Better, more economical use of materials Flame cutting plate is a wasteful process--one of several fabricating steps that consumes more material than needed to make such parts as rings or hubs. Even more is lost in subsequent machining.
Lower scrap; greater, more cost-effective production Forgings, especially near-net shapes, make better use of material and generate little scrap. In high-volume production runs, forgings have the decisive cost advantage.
Fewer secondary operations required As supplied, some grades of bar and plate require additional operations--such as turning, grinding and polishing--to remove surface irregularities and achieve desired finish, dimensional accuracy, machinability and strength. Often, forgings can be put into service without expensive secondary operations.



Compare North American Forges to Offshore Competition
Established quality standards Not every offshore forger can meet domestic product quality standards. Disparities in quality erase price advantages and add costs for rework, delayed production and postponed deliveries.
Lower administrative, sales costs Offshore forgings carry costs that accumulate in the purchasing process--telephone/telex charges, transcontinental air fares and overseas freight charges. The cost of domestic forgings does not include these added expenses.
Technical assistance, flexible deliveries, better service North American forgers commonly provide pre-production engineering assistance and after-sale service, and can offer transport/delivery services timed to meet production requirements. Offshore suppliers offer these only to the "preferred" purchaser.
No cultural, trade or language barriers North American forgers deliver product unimpeded by language differences, variable currency values, tariffs, and unfamiliar tool/material specs that extend lead times, delay production and affect profitability. Common business misunderstandings and problems are more easily resolved at home.
Advantages of North American transport, distribution network The North American transportation networks offer advantages in delivery and shipment that pay off in production costs and product price. North American transport and distribution routes mean timely deliveries--enabling forgers to ship reliably to Just-In-Time production and delivery schedules.
Disadvantages of foreign subsidies and industrial policies Subsidies give offshore suppliers some advantages, but they are only as competitive as their governments permit. Their politics affect their competitive abilities and policies.

This technical information has been contributed by
The Forging Industry Association

Click here to find suppliers

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