The Buyers’ Guide on Forging Components

Close collaboration has always been an important aspect for buyers and producers of forgings to attain the best possible product at the lowest possible cost. As forging methods and materials are greatly improved, this cooperation is more and more crucial. A deal of high-quality products with critical cost savings can be achieved through keeping pace with these improvements, and closely cooperate with the forger, the engineer, or buyer.

 

Although forging has a long-period history and has experienced many technological improvements in recent years, it still plays an important role in technology industry. Even as product designers and industrial buyers know more about forming of metals, putting the forger into design and description stages during the product development can give you much things. At the very beginning of manufacture, questions such as whether a given part can or should be forged must be solved firstly. Nevertheless, this kind of part can be produced with many different processes. 

 

Once it is determined that the strength, toughness, dimensional accuracy and entire integrity is demanded for a product or component, which forging process is most proper is still a question. You have to select from forging process, including open die, impression die, ring rolling, etc.. This decision is often directly achieved, depending on requested part, size, configuration and quantity. But the forging buyer should know something about the ways and equipment applied in the industry, so as to take control of the situation when the decision is uncertain.

 

Besides the common sense about forging, buyers should clearly know what they really need, and how easy the forgers can satisfy their requirements. Different corporation has various capacities. For example:

 

The buyer can reduce the scope of forgers to a few qualified ones by the answering to these questions above. Then he or she is able to capitalize on the estimable technique and design assistance that can be gained from these forging experts.

 

A sophisticated and competent forging corporation engineer should have the ability to give design suggestions to enhance parts, deformalize process, cut down needed machining, accelerate delivery etc. If there is no remarkable increase of material of production costs over those associated with other processes, it may be still likely to attain forging’s high-level performance values.

 

Having the forger involved early is the critical part. The amount of the consultation benefit will depend on the complexity of the component and the forging process. For example, the profit of impression die forgings may be larger than open die ones. But to get the most from a forged component, the proper first step is to establish a team with the product’s designer, the sourcing manager, and a quality management or producing representative. After that this team should sit together with a technical representative of the forging corporation during the process when the product or component design is still being estimated.

 

During the early conferences with candidate forgers, the highlight may be an engineering picture. The part print should be specified so as to present final sizes and tolerances.The needed machining envelope should be fully detailed, if the forging is to be transported in a rough-machined or as forged states. On various occasions, providing a chart which presents the way that the forged part will mate with other parts in the ultimate assembly may be favorable.

 

And another important point should be the service needed to the application.The forgers need to know clearly about the way the forging will be used, the environment for operation, and critical mechanical characters. Completely knowing service stresses such as load-bearing, power transmitting, impact, hydraulic pressure, high or low temperatures, corrosive conditions, and the stress position can make the forger able to make design and process suggestions which may lead to an advanced product and decreased producing costs. For example:

 

Selective carbon-and alloy-steel grades can usually produce similar mechanical properties, which is based on forging design, heat treating, etc. Specifying property levels which exceeds those in fact ordered by the application will remarkably rise the costs. While tensile, strength, influence and other mechanical natures are really based on the required service of the parts being designed, the best price can be attained. As soon as these realistic property levels are set, the forger can help choose one material from the selections to achieve the most favorable combination of performance, economy, and the ability of forging, heat treating and machining.

 

The accomplishment of the specified component structure and the expected grain flow pattern may or may not need particular performing operations, reheats or other dies and equipment. Generally, an experienced forger is able to work with a product design and attain material and production economies with no performance loss. Sometimes, simplification of forging demands, decrease of die costs and acceleration of production can be achieved by slightly changing the shapes of component. 

 

The forging engineer learns a new design from the aspect of its tooling and processing demand. For example, reduced draft angles or sharper radii can sometimes cut machining demand with no influential component function. It may be more likely to produce components with a few costs, if a simpler die can be applied or the parting line can be adapted to allow use of a flat top die.

 

Nowadays forgers have the improved ability to produce as-forged shapes to tight tolerances. Many corporations are struggling to advance their abilities of net- and near-net shape forging. But now holding tight as-forged tolerances still cost much money. If the buyer is wise enough, he or she will ask the forger to help estimate the trade-offs between cut machining and risen die and processing costs.

 

Almost all forgings need to be machined, especially in open die forging. It is a complicate decision for the forger on deciding the place and the amount of money that machining stock or “envelope” should be specified. However, it is important to consider these tolerances as a part together with all sizes on the component chart which is given to the forging engineer whatever they are established. The forger can accept or require specified alteration to get more cost-effective production, which depends on the information above, the forger’s skills and the skills of the steel provider.

 

A series of dimensional tolerances guidelines has been advanced for the forging industry during the past few years, which impose restrictions on size (length, width and thickness), die match and straightness. For example, applying guidelines of impression die can be found in Forging Industry Association’s Tolerances for Impression Die Forgings.

 

Industries have also used these standards in some material considerations such as chemistry, strength, the ductile and conduct ability, influence resistance and grain flow. Corporations such as ASTM, Society of Automotive Engineers, and the American Standards Association, have already published these standards. It is the best way to comply with the defined standards to prevent additional costs, if there is no good reason to decide a special material or tighter tolerance control.

 

A lot of corporations have the abilities of machining and a few provide massive conditioning services. That the forger should accomplish coarse machining is required by many buyers, and they think by doing that, any blemish can be found before the components are freighted and transported by ship. And the number of buyers that order the forgers to do finish machining is increasing, due to economic reasons and responsibility isolation. The purchaser acquires a finished, ready-to-install part, and e The forger is also able to save costs for the buyer due to the added responsibility. The forger is able to accomplish a desired forging around the finished component if he or she is provided with a painting presenting finished component sizes and tolerances. The parting line can be put for making the component quality as good as possible and the production more efficient. But the main advantage is that material and machining time can be saved by reducing the machining envelope.

 

What should be specified to cut the costs as much as possible are only those tests that are required to set up the mechanical properties and quality needed for responsible function. The forger is able to provide good recommendations to proper testing, while the buyer will generally specify the kind of tests and accepted degree requested for a forging. Tests on representative bar samples are relatively simple. Cost will rise when the buyer specified that other tests be made on the forging itself. Non-destructive testing, such as ultrasonic and magnetic granule examination, is more and more critical for important service applications such as generator or turbine rotor shafts. However, these should be applied only when they are necessarily needed, because they may take much time and money. Many forge shops adapt the techniques of quality controlling by statistic process. This may decrease the buyers’ demand for some of the costly testing of perspective forgings. 

 

It is useful to negotiate production amount and expected shipping time tables with the anticipated forger, while it is not so critical in the early stage of design discussions. This can help him take account of these elements when deciding to tooling.

 

In addition, production-run setup and material acquisition demand are based on expected production amount. Advance planning can help extensively reduce the costs in material and production. And compared with shipping to a monthly, weekly, or daily schedule, it is usually cheaper to forge and transport a number of components for just once. However, any economies realized through bulk handling must be balanced against those that may be achieved through just-in-time material-control programs. The forger is always able to make these conflicting factors comply with each other.

 

The process of developing technology and techniques is promoted by the forging industry. Some of the developing processes in the industry nowadays may influence the producing amount of many forgings, whereas others may just have an impact on a small range of the industry. Anyway, it is critical for the forging purchaser to keep pace with the industry developing process, so that he is able to realize what can be chose by advancing technology. This is another way for the expected forger to be earlier get involved in product-development discussions. The experienced forging engineer has the ability to find out circumstance on which the buyer’s special task can be benefit by new technology and processing techniques. Also, only the forger himself is able to decide on how cost-effectively a very new or more developed program can be used in his plant, for the abilities of forging plant are so widely different from each other.

 

The following are fields in which technology is altering the method forgings are made:

A. The Forging of Net Shape Components. 

Due to its potential reduction of finishing costs, net shape forging has received much notice from industries. It should not only be likely to cut the number of stock machined away after forging, but the costs of machining time should also be lower.

 

It doesn’t say that learning net-shape techniques cannot achieve any profits. The experienced forger should have the ability to reduce machining and related expenses as much as possible with a certain level of selecting material and designing forging. The more the forger has put in the early periods of product advancement, the more possible near-net shapes can be accomplished.

 

B. Micro-alloyed Steels. 

These materials are applied to cut or limit the demand for heat treatment and forge some components such as crankshafts, connecting rods and front axles for trucks, together with following cost and energy savings through closely collaboration between forging producer and the buyer, which is needed to guarantee the function matures of the finished products are adapt to the application.

 

C. CAD/CAM, Process Simulation and Computer Control. 

It has transmitted the process of forging from an art to a science. Computers are playing an important role in the daily operations of a forging plant, whether quotations and process simulation or computer control of the forging equipment. Getting the forger engineer involved in the design process usually lead to cutting times, improving the unify from part to part, optimizing heat treating and decreasing the number of materials being moved in machining.

 

The regular forge plant is basically an organization for service. One of the most critical points of the service offered is that the forger can help in the design and advancement of a product which is to be forged. The buyer is now permitted to require and receive ever-higher levels of service from the corporations competing for the business, due to the competition among forgers in the market around the world.

 

With the development of materials and process technologies, it is more and more critical for the forging buyer to get the forger involved in determination that will finally have an impact on the cost and function of the component. Buyers are able to receive the biggest profits from forging industry innovation and also help accelerate the future development by closely cooperating with forgers.