scholarly journals Relationship of the method of obtaining the original billet with the accuracy of manufacturing of the extended axisymmetric bodies

2020 ◽  
pp. 25-28
Author(s):  
A. S. Yamnikov ◽  
E. N. Rodionova ◽  
I. A. Matveev
Keyword(s):  
Heat Treatment ◽  
Quality Parameters ◽  
Rolled Stock ◽  
Low Temperature Annealing ◽  
Rotary Drawing ◽  
Output Quality ◽  
Statistical Studies ◽  
Hot Rolled ◽  
Relationship Of ◽  
Axisymmetric Bodies

A comparative description of the technology for producing blanks for the artillery shell cases or the rocket shell bodies using flat rolled stock or rolled tubular products is given. It is noted that the lower cost of flat rolled stock leads to its wider application for stamping blanks of cartridge caps or bodies, including cutting a circle from flat rolled stock, convolution and several transitions of drawing, alternating with heat treatment. It is noted that the disadvantage of this technology are the errors in the shape of the blanks, amounting to 0.75÷1.5 of the tolerance for diametrical dimensions. When machining, these errors decrease according to the laws of copying the errors, however, the anisotropy of the material of the part blank leads to the appearance of errors in the shape-ovality and curvature of the pipe, which lead to the formation of a large radial runout of the prefabricated rocket body. It has been found that the scattering fields of all output quality parameters exceed the existing tolerances: radial runout of the assembled body by 1.3 times; ovality of the middle centering bulge by 2.15 times. It is shown that the technological process of manufacturing prefabricated housings using initial blanks from flat rolled stock does not provide the required precision technology reliability. For the manufacture of monolithic extended axisymmetric bodies, hot-rolled thickwalled pipes are used as an initial billet. The operations are performed in the following sequence: cutting pipes into dimensional workpieces; machining (turning, boring); heat treatment (quenching, tempering); machining (fine turning, boring); rotary drawing (first and second transitions); crimping the thickening; low temperature annealing. Statistical studies have found a regression equation showing at a confidence level β = 0.95, dependence of the diameter of the base hole of the workpiece after drawing in from the current value of the diameter before drawing.

Relationship of Microstructure and Mechanical Properties in Er-Containing Aluminum Alloy

2015 ◽  
Vol 1120-1121 ◽  
pp. 1109-1114
Author(s):  
Xin Lei ◽  
Hui Huang ◽  
S.P. Wen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloy ◽  
Treatment Process ◽  
Mg Alloys ◽  
The Other ◽  
Heat Treatment Process ◽  
Comprehensive Performance ◽  
Relationship Of ◽  
Al Mg Alloys

This study investigated the mechanical properties and microstructures of Er-containing Al–Mg alloys. The research found that the H114-T sheet of Er-containing Al–Mg alloys showed a relative good comprehensive performance in mechanical properties. With the special rolling and heat treatment process, this H114-T sheet showed different morphology of microstructures with the other sheets in Er-containing Al–Mg alloys. Grains in H114-T sheet performed irregular shape polygon, a number of subgrains appeared in grains, the amount of dislocations in grains decreased. H114-T sheet possessed a lot of Copper texture, this may be one of important factors influenced the mechanical properties.

Network Carbide Inheritance during Heat Treatment Process of Large Shield Machine Bearing Steel GCr15SiMn

2015 ◽  
Vol 817 ◽  
pp. 115-120 ◽  
Author(s):  
Dan Zhang ◽  
Le Yu Zhou ◽  
Chao Lei Zhang ◽  
Chao Huang ◽  
Min Zhao ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Bearing Steel ◽  
Treatment Temperature ◽  
Heat Treatment Process ◽  
Soaking Time ◽  
Hot Rolled ◽  
Chinese Standard ◽  
Shield Machine ◽  
Quenching And Tempering

Network carbide inheritance during heat treatment process of large shield machine bearing steel GCr15SiMn was investigated by heat treatment experiments and quantitative metallographic. Samples with the proeutectoid cementite network thickness in the range of 0.19~0.54 μm were obtained by changing austenitizing temperature and soaking time of pearlite transformation. The results show that the network in hot rolled bar can be improved when the pre-heat treatment temperature is 950 °C. When the network thickness is above 0.40 μm, the undissolved cementite networks present in microstructures after quenching and tempering. In a Chinese standard, the network grades are 1.5 and 3.0 degree when the networks thickness are 0.40 μm and 0.54 μm, respectively. The critical network thickness that can be eliminated by heat treatment is 0.29 μm.

Mechanized line for heat treatment of hot-rolled tubes 30?102

Metallurgist ◽  
1973 ◽  
Vol 17 (2) ◽  
pp. 129-130
Author(s):  
A. Ya. Zelikovich ◽  
O. A. Shcherbina ◽  
V. P. Pavlovskii ◽  
V. I. Krivosheev
Keyword(s):  
Heat Treatment ◽  
Mechanized Line ◽  
Hot Rolled

scholarly journals Influence of the heat treatment on the quality of ivy gourd (Coccinia grandis)

2018 ◽  
Vol 36 (1) ◽  
pp. 126-129
Author(s):  
Thaís Inês M Souza ◽  
Cândido A Costa ◽  
Milton NC Chauca
Keyword(s):  
Heat Treatment ◽  
Titratable Acidity ◽  
Quality Parameters ◽  
Soluble Solids ◽  
The North ◽  
Randomized Design ◽  
Significant Difference ◽  
Minas Gerais State ◽  
Processing Techniques ◽  
Ivy Gourd

ABSTRACT Ivy gourd is an underutilized vegetables found in the North of Minas Gerais State-Brazil. It is mainly consumed raw as salad. Pickling fruits can enhance the commercial exploitation of this species. However, no information on the processing techniques of the ivy gourd fruits in Brazil is found in literature. The objective of this study was to evaluate the quality parameters in the production of pickled ivy gourd. The treatments consisted of three bleaching times (3, 6 and 9 minutes), using a completely randomized design, with seven replicates. We evaluated the traits: instrumental analyzes of pH, color, total titratable acidity, soluble solids, texture and sensorial affective tests. The pH is within the indicated range (below 4.5) and the bleaching time influenced the color and texture alteration since the sample under 3-minute bleaching presented a greater tendency for green and greater firmness. For the sensory analysis, no significant difference related to sensory scoring was noticed; in relation to mode value, we concluded that the 6-minute sample was more preferable, though. For titratable total acidity and soluble solids analyses, no significant differences between the samples was noticed, considering that both parameters were within the standard when compared to other literature. We concluded that heat treatment influenced only the texture and color intensity and the preserved product showed good acceptability.

scholarly journals Resource-saving preparation of the 38KHGNM steel surface for heading of automobile components

2020 ◽  
Vol 157 ◽  
pp. 01006
Author(s):  
Aleksey Filippov ◽  
German Pachurin ◽  
Diana Goncharova ◽  
Gor Gevorgyan ◽  
Mariia Mukhina ◽  
...  
Keyword(s):  
Surface Defects ◽  
Metal Flow ◽  
Steel Grade ◽  
Metallographic Analysis ◽  
Rolled Stock ◽  
Resource Saving ◽  
Cold Upsetting ◽  
Automobile Components ◽  
Hot Rolled ◽  
Decarburized Layer

To produce high-quality fasteners for motor group components of automobiles it is necessary to follow the increased requirements to calibrated rolled stock in terms of surface defects. Therefore, the goal of this paper is to study the reasons, types and depth of the surface defects on the calibrated rolled stock from steel 38KHGNM Ø 12.0 mm on the basis of the metallographic analysis. Before cold upsetting, the hot-rolled products are subjected to metal flow and removal of unacceptable surface defects by means of expensive turning operation during which the screw cuts and cracks might appear. It has been defined, that the hot-rolled stock from steel, grade 38KHGNM, diameter 12.0 мм has nonuniform mechanical properties, grooves, laps and partial decarburization on the surface. The heat treatment of the rolled stock with a decarburized layer on the surface contributes to its further decarburization. Poor alignment of calibrated stock during its turning at the turning machine does not enable to completely remove the decarburized layer with minimum skinning of rolled stock. It has been shown that the use of rolled stock from steel 38KHGNM with surface defects and unreasonably high decarburized layer on the surface increases its rejection by 8% and raises the consumption of rolled stock for manufacturing of important fasteners for the motor group of automobiles.

Study on the Heat-Treatment of Clad Plate for Cutting Tools

2013 ◽  
Vol 401-403 ◽  
pp. 916-919
Author(s):  
Lin Lin Yuan ◽  
Jing Tao Han ◽  
Jing Liu
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Cutting Tools ◽  
High Hardness ◽  
Core Layer ◽  
Water Cooling ◽  
Treatment Processes ◽  
Uniform Microstructure ◽  
Hot Rolled ◽  
Cutting Tool Materials

High sharpness, abrasion resistance, superior ductility, and processability are required in cutting tool materials application. Used 304(0Cr18Ni9) austenitic stainless steel as cladding and 440(7Cr17) martensitic stainless steel as core layer to produce excellently combined stainless steel plate by hot-rolled bonding in this investigation as well as researched various heat treatment processes. The results indicated that the core layer has high hardness and the cladding layer has tiny and uniform microstructure by the method of heating at 10501070°C for 15 minutes, water-cooling , then tempering at 200°C.

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