The Effect of Dwell Time on Die Wear in High Speed Hot Forging

1970 ◽  
Vol 185 (1) ◽  
pp. 1171-1186 ◽  
Author(s):  
S. M. J. Ali ◽  
B. W. Rooks ◽  
S. A. Tobias
Keyword(s):  
High Speed ◽  
Dwell Time ◽  
Hot Forging ◽  
High Energy ◽  
Low Alloy Steels ◽  
Die Wear ◽  
High Energy Rate ◽  
Alloy Steels ◽  
Small Force ◽  
Improved Performance

This paper describes an automatic high energy-rate forging system, consisting of a Petro-forge machine linked to an induction furnace with an automatic billet transfer mechanism. The system contains also automatic die lubrication, as well as pyrometric and other safety interlocks, permitting the feeding and forging of hot billets at a rate of one every 5 s. Hot upsetting tests carried out with this automatic forging system, aiming at the determination of the effect of dwell time on die wear, are discussed. Two series of experiments were carried out, with dwell times of 40 and 250 ms respectively. In the shorter dwell time tests, five different die materials were evaluated with the aim of establishing their relative wear resistance. It was found that the higher alloyed die steels offer improved performance over the conventional low alloy steels, ‘good value for money’ being obtained by WEX 779. An analysis of the dwell time, performed by taking a high speed cine film of the whole forging operation, showed that it consisted of forging, bouncing and after-forging phases. In both the short and the long dwell time tests the forging phase and the bouncing phase were 4 and 30 ms, respectively. However, the after-forge phase was 6 ms for the short dwell time and 216 ms for the long dwell time experiments. During the after-forge phase, the dies, with the upset workpiece between them, are pressed together by a relatively small force and in view of this heat transfer is poor. Nevertheless, the increase of the dwell time has a very large effect on die wear, doubling the rate of wear in some cases, depending on the type of die material used.

Materials for bullet core

2020 ◽  
Vol 2020 (10) ◽  
pp. 8-21
Author(s):  
A. G. Kolmakov ◽  
◽  
I. O. Bannykh ◽  
V. I. Antipov ◽  
L. V. Vinogradov ◽  
...  
Keyword(s):  
High Speed ◽  
Bending Strength ◽  
Low Alloy Steels ◽  
Hard Alloys ◽  
Small Arms ◽  
Alloy Steels ◽  
Materials Used ◽  
Basic Ideas ◽  
New Generation ◽  
Natural Composite

he basic ideas about the process of introducing cores into protective barriers and the most common core patterns and their location in conventional and sub-caliber small arms bullets are discussed. The materials used for manufacture of cores are analyzed. It is concluded that for mass bullets of increased armor penetration the most rational choice can be considered the use of high-carbon low-alloy steels of a new generation with a natural composite structure and hardness of up to 70 HRC. For specialized armor-piercing bullets, cores made from promising economically-alloyed high-speed steels characterized by a high complex of «hardness—bending strength» are better alternative than ones made of hard alloys or tungsten alloys.

Explosive Metalworking: Experimental and Numerical Modeling Aspects

2013 ◽  
Vol 767 ◽  
pp. 138-143
Author(s):  
Andras Szalay ◽  
Athanasios G. Mamalis ◽  
István Zador ◽  
Achilleas K. Vortselas ◽  
Laszlo Lukacs
Keyword(s):  
High Speed ◽  
Electrical Energy ◽  
High Energy ◽  
New Paradigm ◽  
High Explosives ◽  
Explosive Compaction ◽  
Production Of Knowledge ◽  
Knowledge Based ◽  
High Energy Rate ◽  
Compaction Of Powders

The application of the High Energy Rate Forming (HERF) represents a new paradigm in the field of production of knowledge-based more components materials: furthermore, joining by plastic deformation of the materials is carried out directly, by high speed, high energy shock waves, without using energy transforming equipment as hydraulic presses etc. The energy sources of the HERF processes are either the electrical energy stored in capacitors or chemical energy stored in the high explosives. High explosives can be utilized for many metalworking techniques; however the three main types of explosive metalworking are: Explosive welding and cladding Explosive tubeforming Explosive compaction of powders and granulates. The present work briefly introduces the principles and practices of the three main types of the explosive metalworking techniques mentioned above and discusses aspects of their numerical simulation.

Design and Development of a Compressed-Air Driven, Counterblow High Energy-Rate Forming Machine

1965 ◽  
Vol 180 (1) ◽  
pp. 777-789
Author(s):  
I. Marland ◽  
A. J. Organ ◽  
S. A. Tobias
Keyword(s):  
High Speed ◽  
High Energy ◽  
Maximum Energy ◽  
Compressed Air ◽  
Energy Output ◽  
Net Energy ◽  
Energy Rate ◽  
High Energy Rate ◽  
Approach Velocity

As a first stage in the development of a large, double-acting, petrol combustion actuated, high energy-rate forming machine, a compressed-air driven device was designed and constructed. This was intended to be a research vehicle for establishing general design principles, particularly as far as the structural configurations and the method of platen synchronization were concerned. The characteristic design features of this machine are discussed and an appraisal of the design is given. Experiments were carried out with the aim of (1) determining the net energy output of the machine and (2) finding the maximum platen approach velocity for a range of values of the initial charge pressure. For the determination of the energy output of the machine, calibrated crush-gauges were used, the results being cross-checked by measuring the maximum relative velocity between the platens, and from this and the weight of the moving masses finding the maximum kinetic energy. For the determination of the maximum platen approach velocity, electric velocity transducers were used, the results being checked with the aid of a high-speed ciné camera. The maximum energy output of the machine was found to be 75 000 ft lb, which was attained with a maximum impact velocity of 80 ft/s, as aimed at in the design of the machine. Some typical examples of hot forgings produced with the machine are also presented.

Effect of Hot Work on Hardness and Impact Toughness of Heat Treated Low Alloy Steels

2014 ◽  
Vol 1082 ◽  
pp. 197-201
Author(s):  
Mahmoud M. Tash ◽  
Saleh A. Alkahtani ◽  
Khaled A. Abuhasel
Keyword(s):  
Impact Toughness ◽  
Hot Forging ◽  
Weight Ratio ◽  
High Strength ◽  
Extensive Study ◽  
Low Alloy Steels ◽  
Alloying Additions ◽  
Heat Treated ◽  
Alloy Steels ◽  
Effect Of Hot Rolling

The present study was undertaken to investigate the effect of hot work reduction ratio on the hardness and impact toughness of different grades of low alloy steels. The effect of hot rolling and hot forging with different reduction ratios on the hardness and impact toughness properties will be studied. An extensive study will be carried out to investigate the effect of alloying additions and TMT parameters on the hardness and impact toughness of heat-treated low alloy steels. An understanding of the combined effect of TMT and heat treatment on the hardness and impact toughness of the low alloy steels would help in selecting conditions required to achieve optimum mechanical properties and alloy high strength to weight ratio.

Structure and properties of P/M low-alloy steels produced by hot forging

1983 ◽  
Vol 22 (4) ◽  
pp. 302-304
Author(s):  
I. D. Radomysel'skii ◽  
V. N. Klevtsov ◽  
S. G. Napara-Volgina ◽  
I. D. Martyukhin ◽  
A. K. Gaiduchenko ◽  
...  
Keyword(s):  
Hot Forging ◽  
Low Alloy Steels ◽  
Structure And Properties ◽  
Alloy Steels

High Speed Impact Extrusion of Metals

1965 ◽  
Vol 180 (1) ◽  
pp. 191-215 ◽  
Author(s):  
B. N. Cole ◽  
R. Davies ◽  
E. R. Austin ◽  
F. Bakhtar
Keyword(s):  
High Speed ◽  
High Energy ◽  
The Other ◽  
Compressed Air ◽  
High Speed Impact ◽  
High Energy Rate ◽  
Aluminium Copper ◽  
Wide Range ◽  
Cold Metal ◽  
Striking Velocities

The paper describes an investigation of high speed or ‘high energy-rate’ extrusion of cold metal billets. Preliminary trials were carried out with a small pilot machine which, with low explosive drive, could supply up to 430 ft lb per blow at a striking velocity of 132 ft/s. Main trials were subsequently completed using two ‘full-scale’ machines, one explosively driven and the other driven by compressed air, designed to be complementary to each other in such a way that a wide range of energies and striking velocities could be achieved, up to 10 000 ft lb and over 300 ft/s. The metals used were aluminium, copper and mild steel, all in the annealed state. In the main the experience gained was satisfactory and encouraging, and while it was concluded that impact velocities of the order of 50–100 ft/s are feasible, it appeared that the disadvantages of much higher velocities would outweigh the advantages.

Processing with Nitriding

2003 ◽  
pp. 153-161
Keyword(s):  
High Speed ◽  
High Speed Steel ◽  
Compound Layer ◽  
Case Depth ◽  
Low Alloy Steels ◽  
Layer Formation ◽  
Tool Steels ◽  
Maraging Steels ◽  
Alloy Steels ◽  
Hot Work Tool Steels

Abstract The nitriding process can be applied to various materials and part geometries. This chapter focuses on tool steels (hot-work tool steels, high-speed steel cutters, and gears), pure irons, low-alloy steels, and maraging steels. Various considerations such as the surface metallurgy requirements of the die, including case depth, compound layer formation, and temperature, are also discussed in this chapter.

A Digital System for the Recording of Impact Velocity, Acceleration and Forming Load of a High Energy Rate Forming Machine

1987 ◽  
Vol 109 (4) ◽  
pp. 392-396
Author(s):  
O. Derriche ◽  
D. C. Hodgson
Keyword(s):  
Solid State ◽  
Impact Velocity ◽  
Metal Forming ◽  
High Speed ◽  
High Energy ◽  
Displacement Velocity ◽  
Forming Load ◽  
High Energy Rate ◽  
Moving Body ◽  
Digital Nature

A noncontacting device has been developed to measure the instantaneous displacement, velocity, or acceleration of a moving body. The device, based on a solid-state camera, has been used to measure some of the main parameters in a high-speed metal forming operation, though in principle it could be applied to almost any moving body. Errors associated with the digital nature of the measurement are discussed and evaluated.

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