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.

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.

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.

Probabilistic Properties of Steel for Nuclear Piping

2018 ◽  
Author(s):  
Kleio Avrithi
Keyword(s):  
Mean Value ◽  
Background Information ◽  
Low Alloy Steels ◽  
Target Reliability Index ◽  
Alloy Steels ◽  
Factor Design ◽  
The Mean ◽  
Materials Used ◽  
Load And Resistance Factor ◽  
The Impact

For the development of design rules for nuclear piping using the Load and Resistance Factor Design (LRFD) method, the probabilistic properties of steel, namely, the mean value, bias, coefficient of variation, and probability distribution are needed. The paper presents background information for the existing material tables in the ASME Boiler and Pressure Vessel Code, Section II. Then it investigates the probabilistic properties for the most representative materials used for nuclear piping such as a carbon, stainless austenitic, and low alloy steels. Properties up to temperature 700°F are examined through a review of studies for the mechanical behavior of these materials. The paper discusses approaches for grouping materials in broader categories than the consideration of each type of steel separately. The impact of the steel probabilistic properties on the development of LRFD equations and the associated target reliability index is provided.

The Effect Covering on the Change in the Properties of Hard Alloys

2021 ◽  
Vol 887 ◽  
pp. 376-382
Author(s):  
S.I. Bogodukhov ◽  
E.S. Kozik ◽  
E.V Svidenko ◽  
V.S. Garipov
Keyword(s):  
Hard Alloy ◽  
High Speed ◽  
Manufacturing Industry ◽  
Bending Strength ◽  
High Speed Steel ◽  
Physical And Mechanical Properties ◽  
High Hardness ◽  
High Heat ◽  
Hard Alloys ◽  
Operational Parameters

Currently, hard alloys are common tool materials; they are widely used in the tool manufacturing industry. Due to the presence of refractory carbides in its structure, hard-alloy tools feature a high hardness of 80 to 92 HRA (73 to 76 HRC); a high heat resistance (from 800 °С to 1,000 °С); therefore, they can be used at speeds that are several times higher than cutting speeds of high-speed steel grades. Hard alloys are used in the form of plates that are either mechanically fixed on or soldered to tool holders. The main operational parameters, that determine the hard-alloy tool operation mode, are hardness, wear resistance, and bending strength. The operational parameters of alloy are highly dependent on its structure, phase composition, lattice block sizes, and micro-stress values [1-20]. The main methods to enhance physical and mechanical properties of hard-alloy plates are improvement of manufacturing technology, including production of fine-grained alloys and microalloying, as well as applying composite coating by vacuum deposition, which allows to increase the tool resistance 1.5 to 2 times.

TUNGSTEN-FREE HARD ALLOYS: MANUFACTURING METHODS, STRUCTURE AND PROPERTIES (review)

2021 ◽  
pp. 66-81
Author(s):  
A.Yu. Patrushev ◽  
◽  
D.P. Farafonov ◽  
M.M. Serov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Work ◽  
Carbide Phase ◽  
High Speed ◽  
Physical And Mechanical Properties ◽  
Hard Alloys ◽  
Structure And Properties ◽  
Technical Literature ◽  
Manufacturing Methods ◽  
New Generation

In this paper provides an overview of scientific and technical literature and developments in the field of tungsten-free hard alloys or cermet as promising materials of a new generation metalworking tools. Methods of obtaining sintered hard alloys, their structure and basic operational properties are considered The main directions of improving the properties of hard alloys are given. The results of experimental work on the production of cermet by high-speed quenching of the melt are presented. The obtained fast-quenched materials of the Fe–TiC–TiB2 system demonstrate physical and mechanical properties at the level of sintered hard alloys, but at the same time it contain 2–3 times less of the carbide phase.

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