Jump to content
I Forge Iron

sgtlethargic

Members
  • Posts

    12
  • Joined

  • Last visited

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

  1. I read and appreciate all of the responses. I did a little research (yes, I used Wikipedia, which some people seem to despise). This is a supposition about forging. This forum seems to be geared to traditional (hand) forging, and I believe this is considered not traditional since it’s done using machines. The basic idea is:  Forge cylinders/rods  Closed-die, press forged  Machine to final part If one can buy forged rod stock, then the above is moot. The basic plan is:  Machine an closed-die to form a simple cylinder/rod  Simple die: a block with a hole bored, then split in half  Experiment and determine the size and shape of raw material rod stock to form a properly forged cylinder  Heat one rod to the proper forging temperature (also to be determined)  Place heated rod into die  Press  Post-treatment? “The devil is in the details”, but does this make sense? http://en.wikipedia.org/wiki/Forging [i copied and pasted the text I think is relevant, and bolded the more important parts.] There are many different kinds of forging processes available, however they can be grouped into three main classes:[1] Drawn out: length increases, cross-section decreases Upset: length decreases, cross-section increases Squeezed in closed compression dies: produces multidirectional flow Common forging processes include: roll forging, swaging, cogging, open-die forging, impression-die forging, press forging, automatic hot forging and upsetting.[ One variation of impression-die forging is called flashless forging, or true closed-die forging. In this type of forging the die cavities are completely closed, which keeps the workpiece from forming flash. The major advantage to this process is that less metal is lost to flash. Flash can account for 20 to 45% of the starting material. The disadvantages of this process include additional cost due to a more complex die design and the need for better lubrication and workpiece placement. Closed-die forging has a high initial cost due to the creation of dies and required design work to make working die cavities. However, it has low recurring costs for each part, thus forgings become more economical with more volume. This is one of the major reasons closed-die forgings are often used in the automotive and tool industry. Another reason forgings are common in these industrial sectors is because forgings generally have about a 20 percent higher strength-to-weight ratio compared to cast or machined parts of the same material. Press forging Press forging works by slowly applying a continuous pressure or force, which differs from the near-instantaneous impact of drop-hammer forging. The amount of time the dies are in contact with the workpiece is measured in seconds (as compared to the milliseconds of drop-hammer forges). The press forging operation can be done either cold or hot.[10] The main advantage of press forging, as compared to drop-hammer forging, is its ability to deform the complete workpiece. Drop-hammer forging usually only deforms the surfaces of the workpiece in contact with the hammer and anvil; the interior of the workpiece will stay relatively undeformed. Another advantage to the process includes the knowledge of the new part's strain rate. We specifically know what kind of strain can be put on the part, because the compression rate of the press forging operation is controlled. There are a few disadvantages to this process, most stemming from the workpiece being in contact with the dies for such an extended period of time. The operation is a time consuming process due to the amount of steps and how long each of them take. The workpiece will cool faster because the dies are in contact with workpiece; the dies facilitate drastically more heat transfer than the surrounding atmosphere. As the workpiece cools it becomes stronger and less ductile, which may induce cracking if deformation continues. Therefore heated dies are usually used to reduce heat loss, promote surface flow, and enable the production of finer details and closer tolerances. The workpiece may also need to be reheated. When done in high productivity, press forging is more economical than hammer forging. The operation also creates closer tolerances. In hammer forging a lot of the work is absorbed by the machinery, when in press forging, the greater percentage of work is used in the work piece. Another advantage is that the operation can be used to create any size part because there is no limit to the size of the press forging machine. New press forging techniques have been able to create a higher degree of mechanical and orientation integrity. By the constraint of oxidation to the outer most layers of the part material, reduced levels of microcracking take place in the finished part.[10] Press forging can be used to perform all types of forging, including open-die and impression-die forging. Impression-die press forging usually requires less draft than drop forging and has better dimensional accuracy. Also, press forgings can often be done in one closing of the dies, allowing for easy automation. Cost implications To achieve a low cost net shape forging for demanding applications that are subject to a high degree of scrutiny, i.e. non-destructive testing by way of a dye-penetrant inspection technique, it is crucial that basic forging process disciplines are implemented. If the basic disciplines are not met, there is a high probability that subsequent material removal operations will be necessary to remove material defects found at non-destructive testing inspection. Hence low cost parts will not be achievable.[citation needed] Example disciplines are: die-lubricant management (Use of uncontaminated and homogeneous mixtures, amount and placement of lubricant). Tight control of die temperatures and surface finish / friction. A forging press, often just called a press, is used for press forging. There are two main types: mechanical and hydraulic presses. Mechanical presses function by using cams, cranks and/or toggles to produce a preset (a predetermined force at a certain location in the stroke) and reproducible stroke. Due to the nature of this type of system, different forces are available at different stroke positions. Mechanical presses are faster than their hydraulic counterparts (up to 50 strokes per minute). Their capacities range from 3 to 160 MN (300 to 18,000 short tons-force). Hydraulic presses use fluid pressure and a piston to generate force. The advantages of a hydraulic press over a mechanical press are its flexibility and greater capacity. The disadvantages include a slower, larger, and costlier machine to operate.
  2. Thanks, Old N Rusty.

  3. hi welcome to IFI playground, it is a learning experience here dont stop posting because of naked guys at anvils or sometkin

  4. Man, I feel terrible. I joined a blacksmith forum and asked some questions and now I got some guy named "Naked Anvil" picking on me. It's just like the playground all over again, aint it Grant?
  5. I'm trying to grasp the concept of press forging. What percentage of volume change is necessary? I imagine the extreme would be the point where the material will not compress any further and the length is going to change, so the dies would have an overflow volume.
  6. I'm just wondering what it takes to forge parts. Both you and I know I'm not going to be making and selling parts any time soon. Maybe it'll take ten years. Maybe it'll be too expensive to bother doing. Maybe, maybe, maybe. What's a good resource or three?
  7. I'll look into the liability issues. The parts would be supplied to a shop that would include them as part of their kit, so that may skirt some liability. On to what it'd take to make a good part. I know next to nothing about forging. Which forging process would you think to use for something like this- press forging? We used a horseshoe forge for heating rivets for restoring a steam locomotive. Is something like that going to be hot enough? What size (tons force) of a press would be needed?
  8. Liability insurance on the part, process, or both?
  9. I'm new here (). I am wondering what it might take to make aftermarket automotive quality forged chromoly parts. The part is an upper control arm shaft, so the size would be about 6" in length and 1/2" in diameter. Is this something that could be done on a small scale? Thanks, Kurt
  10. Hi, New here. I've often thought about machining something for a side business. It'd probably be an old car / hot rod part, maybe something for vintage houses. On another forum there is a thread on "Made in the USA" and "Hecho in China". Someone suggested small production runs, and I'm here to ask about that, especially in the forging department. Thanks, Kurt
×
×
  • Create New...