scholarly journals Pipes production by hot reducing at SKK-14 radial-forging machine

2019 ◽  
Vol 75 (2) ◽  
pp. 242-246
Author(s):  
S. I. Zakarlyukin ◽  
G. I. Koval’
Keyword(s):  
Internal Surface ◽  
Wall Thickening ◽  
Outer Diameter ◽  
Radial Forging ◽  
Longitudinal Rolling ◽  
Corrosion Resistant ◽  
Rotary Forging ◽  
Pilot Work ◽  
Radial Forging Machine ◽  
Small Capacity

At small-capacity production of pipes a process of pipes reducing at radial-forging machines can be effective for expanding of pipes assortment by diameter and wall thickness. Results of pilot work on hot reducing at radial-forging machine SKK14 of pipes, made of corrosion-resistant steels 12Х18Н10Т and 10Х23Н18. Based on analyses of known recommendations on pipes forming during reducing by longitudinal rolling at reducing mills, as well as at radial-forging and rotary-forging machines, it was recommended to use a known dependence Sр = S0/[1 – 0,0044(D0 – Dр)], usually applied for pipes rolling conditions at reducing mills, for predicting of reduced pipe wall thickening. To determine the pipes internal surface quality, a hot reducing of pipes made of 12Х18Н10Т steel was accomplished using different technological routes and taking into consideration a possibility of forming folds and laps on the surface. It was established that longitudinal folds (wrinkles) are not formed on the pipe internal surface at the pipe outer diameter decreasing by less than 30%, while the longitudinal folds (wrinkles) are formed at decreasing of the pipe outer diameter by more than 45%. Forging folds can be formed on the pipe internal surface at pipe outer diameter decreasing by more than 60%.

scholarly journals Obtaining hollow semi-finished products from copper alloys for electrical applications by screw rolling method

2020 ◽  
pp. 27-38 ◽  
Author(s):  
Yu. V. Gamin ◽  
B. A. Romantsev ◽  
A. N. Pashkov ◽  
P. V. Patrin ◽  
I. A. Bystrov ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Copper Alloys ◽  
Reduction Process ◽  
Point Of View ◽  
Wall Thickening ◽  
Relative Reduction ◽  
Outer Diameter ◽  
Screw Rolling ◽  
Front End ◽  
Rolling Method

The article proposes a process for obtaining semi-finished products in the form of pipes made of copper alloys for electrical applications using the screw rolling method. The paper presents the results of experimental piercing and rolling of pipe samples made of Cu–0.75Cr copper alloy billets with a diameter of 45 mm. The 43.5×10.0 mm samples obtained after piercing using a two-roll screw rolling mill had exact geometrical dimensions: outer diameter deviation at the front end was up to 1 %, at the back end – up to 2.4 %; relative variation in wall thickness at the front end was 0.3÷0.5 %, at the rear end – 0.5÷1.0 %. Then pierced pipe samples were rolled using a three-roll radial-shear rolling (RSR) mini mill with a different total degree of reduction – samples were obtained with an outer diameter of 30, 25 and 18 mm. The reduction process was analyzed from the point of view of internal hole stability and deformation. In case of 30 % relative reduction of the outer diameter, rolling without a mandrel is accompanied by wall thickening. In this case, inner diameter deviations are within acceptable limits. The experiments on obtaining samples from the Cu–0.75Cr alloy by screw piercing and reduction in the RSR mill show that this scheme can be implemented in principle in industry. At the same time it is necessary to define more exactly deformation parameters (degree of deformation, choice of reduction scheme) to obtain a quality product. Various options for heat treatment (HT) of the obtained pipe samples and the effect of the HT method on electrical conductivity and hardness are considered. Samples after piercing had a conductivity of 59.3 % IACS. The maximum electrical conductivity of 76.7 % IACS was obtained on samples after quenching from a temperature of 1020 °C and aging at 450 °C for 3 h. The results of the work show the fundamental possibility of obtaining semi-finished products from copper alloys for electrical purposes using the screw rolling method.

Maximum Feed in Forging in a Radial-Forging Machine with the Jigging Motion of Head Levers

2019 ◽  
Vol 2019 (13) ◽  
pp. 1456-1459
Author(s):  
I. I. Nekrasov ◽  
A. A. Fedulov ◽  
V. S. Parshin
Keyword(s):  
Radial Forging ◽  
Radial Forging Machine

Determination of Residual Ductility in the Forging of Bars on a Lever-Type Radial Forging Machine

Metallurgist ◽  
2016 ◽  
Vol 59 (11-12) ◽  
pp. 1122-1124
Author(s):  
A. P. Karamyshev ◽  
I. I. Nekrasov ◽  
V. S. Parshin ◽  
A. A. Fedulov ◽  
A. I. Pugin
Keyword(s):  
Radial Forging ◽  
Radial Forging Machine

A New Approach to Precision Cropping with Radial Forging

2011 ◽  
Vol 291-294 ◽  
pp. 3064-3068 ◽  
Author(s):  
Sheng Dun Zhao ◽  
Bin Zhong ◽  
Yong Tang ◽  
Ren Feng Zhao
Keyword(s):  
Radial Displacement ◽  
Experimental Results ◽  
Feasibility Analysis ◽  
Stress And Strain ◽  
Radial Forging ◽  
New Approach ◽  
Strain Concentration ◽  
Working Principle ◽  
Radial Forging Machine ◽  
Loading Sequence

This paper presents a new approach to precision cropping with radial forging, it skillfully utilizes the stress and strain concentration effect of the prefabricated V-shaped notch and the principle of the radial-forging machine to achieve the regular fracture of metal bar. The basic working principle of the new radial-forging cropping method is discussed in detail. Moreover, the distribution of the radial displacement loads is discussed in detail, and the loading rules are clearly explained under the conditions of the single cropping die, two cropping dies, three cropping dies and four cropping dies, as well as the radial-forging loading sequence. The model and equation of the movement with the radial-forging are established, the feasibility analysis of the radial-forging cropping method is carried out, which is in agreement with the experimental results.

scholarly journals Clinical, Physiological and Radiological Features in Asthma with Incomplete Reversibility of Airflow Obstruction Compared with Those of COPD

1998 ◽  
Vol 5 (4) ◽  
pp. 270-277 ◽  
Author(s):  
Louis-Philippe Boulet ◽  
Hélène Turcotte ◽  
Catherine Hudon ◽  
Guy Carrier ◽  
François Maltais
Keyword(s):  
Pulmonary Function ◽  
Pulmonary Function Tests ◽  
Airflow Obstruction ◽  
Smoking History ◽  
Arterial Oxygen ◽  
Wall Thickening ◽  
Chronic Obstructive ◽  
Outer Diameter ◽  
Exercise Tests ◽  
Copd Patients

OBJECTIVES: To compare clinical features, pulmonary function and high-resolution computed chest tomography (HRCT) findings of asthmatic patients with a component of incomplete reversibility of airflow obstruction (AIRAO) with those of patients with smoking-induced chronic obstructive pulmonary disease (COPD).METHODS: Thirteen patients with COPD (six males and seven females, mean age 59 years, mean smoking 50.5 pack-years) and 14 patients with AIRAO (six males and eight females, mean age 52 years) despite optimal treatment, with no significant smoking history (mean 1.5 pack-years) and no significant environmental exposure or any other respiratory disease, were studied. Patients had respiratory questionnaires, pulmonary function tests, allergy skin-prick tests and an HRCT to evaluate possible parenchymal or bronchial abnormalities. Eight patients in each group also had exercise tests. All patients were stable at the time of the study.RESULTS: As expected, atopy was more prevalent in AIRAO (n=13) than in COPD (n=1) patients. Mean forced expiratory volume in 1 s (FEV1) and forced vital capacity (percentage of predicted value) were 39% and 61%, respectively, in COPD patients and 49% and 71%, respectively, in AIRAO patients; FEV1improved by 18% in COPD patients and and by 22% in AIRAO patients after use of inhaled salbutamol. Mean functional residual capacity was greater in COPD patients than in AIRAO patients (178% versus 144% of the predicted value), while the mean carbon monoxide diffusing capacity of the lungs (DLCO) was lower in COPD patients than in AIRAO patients (62% versus 89% of the predicted value). Exercise tolerance was similar in both groups, as were postexercise changes in arterial oxygen pressure (PaO2). Emphysematous changes were observed in COPD patients and AIRAO patients who had evaluable HRCTs (10 versus two patients, although very mild in asthma), bronchial dilations (zero versus six patients), bronchial wall thickening (two versus eight patients) and an acinar pattern (one versus five patients). Mean thickness of the large airway wall to outer diameter (intermediary bronchus) ratio was 0.176 in COPD and 0.183 in AIRAO (P>0.05).CONCLUSIONS: Asthma may lead to physiological features similar to COPD but may be distinguished by demonstrating a preserved DLCO and a higher ratio of airway to parenchymal abnormalities on HRCT scan.

Studying the damage of ingots under plastic deformation on a lever-type radial forging machine

2016 ◽  
Author(s):  
A. P. Karamyshev ◽  
I. I. Nekrasov ◽  
A. V. Nesterenko ◽  
V. S. Parshin ◽  
S. V. Smirnov ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Radial Forging ◽  
Radial Forging Machine

Production of bottom flange shells by cold extrusion on specialized press

2021 ◽  
pp. 450-458
Author(s):  
A.M. Dmitriev ◽  
N.V. Korobova
Keyword(s):  
Cold Extrusion ◽  
Outer Diameter ◽  
Bottom Flange ◽  
Technological Solution ◽  
Shell Wall ◽  
Corrosion Resistant ◽  
Direct Extrusion ◽  
Intractable Problems

The possibility for manufacturing by cold extrusion of part such as shells made of corrosion-resistant and higstemperature steel is evaluated. It is shown that when extrusion such parts using combination of direct extrusion from workpiece with diameter equal to the diameter of the flange, followed by direct extrusion of the shell wall, number of intractable problems arise. Some of these problems relate to the design of production die to be fitted to mass produced standard presses. It is proposed to manufacture parts of the type using combination of extrusion of the shell walls from workpiece with diameter equal to its outer diameter, with simultaneous radial extrusion of the flange. Such technological solution can be implemented on domestic specialized presses.

Using an AVS radial-forging machine to prepare the ends of tubes for drawing

Metallurgist ◽  
2008 ◽  
Vol 52 (9-10) ◽  
pp. 498-500 ◽  
Author(s):  
A. P. Karamyshev ◽  
I. I. Nekrasov ◽  
V. S. Parshin ◽  
V. A. Systerov
Keyword(s):  
Radial Forging ◽  
Radial Forging Machine
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