Why Our Forgings Are Better
In many industries the mechanical advantages of forgings over castings are well understood. You do not need to look far to find applications where forgings are used for critical mechanical components - where high strength and resistance to failure is mandated.
We have been very successful in forging direct replacements for castings that out perform castings in terms of mechanical properties and economics. We can do this because forgings have two primary advantages:
1. Better mechanical properties:
- Forgings are stronger.
- Casting cannot obtain the strengthening effects of hot and cold working.
- Castings have a narrow range of steel chemistries whereas forging is nearly unlimited.
- Forging surpasses casting in predictable strength properties - producing superior strength that is assured, part to part.
- Forging refines defects from cast ingots or continuous cast bar. A casting has neither grain flow nor directional strength and the process cannot prevent formation of certain metallurgical defects. Pre-working forge stock produces a grain flow oriented in directions requiring maximum strength. Dendritic structures, alloy segregation's and like imperfections are refined in forging.
- Forgings are 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 inspections that are required for casting.
- Forgings offer 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. • Forgings' 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.
2. Economic reasons:
Environmentally speaking forgings are a clean and green solution over castings. Foundries have always been a dirty business. Casting sands and release agents produce airborne pollution as dust and VOCs that must be addressed. Disposal of casting sand is also an environmental cost. Under increasing regulations, the operating costs of foundries will continue to increase. The forging process has none of these issues.
Many customers wonder how we are able to forge a direct replacement for a casting and are perplexed we can deliver a forging that is economically feasible. The simple answer is we have a long history of forging and we know what we are doing. Our production facilities have been well tuned to the parts we make for over a 140 years. We have the right sized hot working equipment and have perfected our heat treating, machining processes and overall work-flow to the point we are very competitive with many castings. Where foundries need a mold for everything they make, we have an advantage of being able to produce unlimited shapes – because we use no molds. Our process becomes more efficient as the part size increases; with castings the inverse is true: As their part size increases their rejection rate increases and their choice in chemistry narrows and the cost goes up. Our company has found a niche in increasing the overlap where forgings and casting compare. We tend to focus on applications where there is high impact and wear involved that demands very specific metallurgy that can only be delivered as a forging. For over 140 years this area of metallurgy and forging has been very well understood by Augustfehn and seated it as the world leader in this area.
The Bottom Line:
Forgings are almost always used in the most critical areas. Paradoxically, the industries we serve traditionally do not use them. What could be more demanding than the impact and wear involved in shredding automobiles or crushing aggregates? Can you imagine flying on a jet liner with cast landing gear? There is a better way and we deliver it.