Four-Block Forging Device

Author: Viktor Lazorkin, Ph.D.
Company: TECHNONOVA Co., Ltd.
Contact info:

Novitskogo, 10, k.2  

69035, Zaporozhye, UKRAINE  

Web site www.technonova.nm.ru  
e-mail technonova@nm.ru

Four-block forging device is the unique apparatus invented by our leading engineers. The use of this device results in:

• increase in productivity of forging by 1.5-5 times
• increase in metal yield by 8-15 %
• increase in metal yield by 8-15 %
• increase in metal recovery by 15-50 % via decreasing tolerances
• energy savings by 1.5-4 times
• improved structural isotropy of metal and its physical-chemical properties
• wide range of steel grades and sectional shapes forgeable

Please find the details below.

Device operation

The device is installed and fastened onto a tool table of a hydraulic or mechanical forging press instead of conventional blocks (dies) and operates as follows:

When upper traverse of press travels down its motion is transferred through the device mechanism resulting in four-side reduction of a workpiece (blank) between blocks of the device. When upper traverse of press travels up the device blocks are moved apart releasing the workpiece. Then the cycle repeats.

ADVANTAGES

Productivity

When forging with two blocks (a conventional method) the workpiece significantly widens on its sides resulting in slower processing as it necessitates additional canting and reduction to be done in order to obtain the workpiece of required length and shape.

When forging with four blocks the workpiece does not widen on its sides or its widening is minimal that leads to less number of canting and reduction needed. This results in increase of forging output.

Moreover, when forging in four-block forging device the workpiece cools down much slower than it does in case of conventional forging with two blocks for account of more intensive heat generation at deformation. Thus, the number of additional heats and duration of the whole cycle of production decreases.

Quality of metal and precision of forged products

Four-side reduction in the forging device provides compressive stresses in surface area of the workpiece making it possible to deform steels and alloys with low plasticity. Thus, forging in this device installed into the press is somewhat similar to forging in radial forging machine (RFM). However, forging in the device is favorably distinguished from forging in RFM with respect to some parameters of forging. Forging in RFM does not allow deforming cast structure of metal uniformly across the whole cross-section of the workpiece. In four-block forging device offered the blocks travel not only in radial direction as those in RFM, but also in tangential direction exciting additional shearing strains in cross-section of the workpiece. Deep deformation of cast structure of metal is possible due to this fact and also owing to increased unit reductions (as compared to forging in RFM). Such defects as porosity of material are not encountered and quality of products forged in the device is higher than that obtained in RFM when forging products of various structural alloyed steels, high-speed tool and stainless steels, high-temperature and heat-resistant alloys. The method of forging developed by our specialists enables tolerances of ± 0.8-2.0 mm depending on cross-section size of the workpiece. Forged workpieces are calibrated in the calibrating device after rough forging without preheating in order to achieve such tolerances. In our opinion, one can apply closer tolerances for products forged in the device than those applied for products manufactured by RFM of such world-known companies as GFM (Austria) and Daniele (Italy).

Metal saving

Four-side scheme of reduction in the device with blocks of special design provides compressive stresses in peripheral ring area of the workpiece to enable forging free of formation of surface defects. This leads to lower metal loss at auxiliary operations and increases metal yield.

Besides, decreased number of additional heats of metal results in lower waste of metal that also leads to higher metal yield saving it.

Energy consumption

Energy consumption diminishes when forging in the device in comparison with conventional forging with two blocks for account of:

• energy savings by 40-50 % in the process of forging;
• decrease in energy consumption (gas, fuel oil, electric power) by 25-40 % owing to lesser number of heats of the workpiece required.

ECONOMIC EFFICIENCY

Four-block forging devices can advantageously be used in hydraulic forging presses of 3 to 100 MN independently of degree of mechanization and automation of the forging process or forging system. The devices are mostly efficient to be used within automated forging systems with two manipulators working simultaneously and the press equipped with a tool (cross) table having mechanized grip of the upper die.

According to our data, forging alloyed structural and tool steels in the devices installed into hydraulic forging presses of 20-40 MN results in:

• reduction of forging productive time required by 35-65 % allowing increase in forging output by 1.7-2.5 times;
• increase in metal yield by 7-13 % due to decrease in surface defects and in number of heats required;
• manufacture of round and square (with sharp edges) products with precise geometry and closer (by 40-60 %) tolerances;
• energy savings per one forging by minimum 1.5 time;
• high quality of metal products obtained.

An approximate year economic efficiency under condition of two-shift work of press of 20 MN equipped with the device (when forging tool steels) is minimum 2 million USD.

The device is specially designed for long trouble-free operation under conditions of forge-and-press production of metallurgic and machine-building plants. Weight of the forging device equals up to 1-7 % of the press weight.

INDUSTRIAL USE

We have an experience of operation of the devices at works in Ukraine including operation of the device in hydraulic forging press of 5 MN at the pilot plant for eight years. Besides, at the moment we are engaged in equipping the hydraulic forging press of 18 MN with our devices by request of a company from Spain. The devices will be used there for forging ingots of alloyed structural steels weighting 3 to 10 tons with diameter of up to 900 mm allowing to increase output of the press by 1.7-2.0 times and to achieve more precise geometry of forged products.

Information supplied by the Author May 2001.  Page last updated: January 19, 2004