Exploring Autofrettage Process to Improve the Fatigue Life on High-Pressure Cylinder

2013 ◽  
Vol 457-458 ◽  
pp. 518-521
Author(s):  
Feng Ling Yang ◽  
Shi Jin Zhang
Keyword(s):  
High Pressure ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Analysis ◽  
High Pressure Cylinder ◽  
Pressure Cylinder ◽  
Surface Variation ◽  
Life Improvement ◽  
Improve Fatigue Strength ◽  
Improve Fatigue

Autofrettage process is now widely used to improve fatigue strength of high pressure components. This paper focuses on the fatigue life improvement of the high-pressure cylinder treated by autofrettage process. In this process, a high pressure cylinder treated by autofrettage process has been simulated by using FEA software, and surface variation of the cylinder has been analyzed. To further understand this process, theoretical fatigue analysis has also been carried out.

The Effect of Shot Peening on the Surface Topography and Fatigue Strength of Selected Sheets

2015 ◽  
Vol 818 ◽  
pp. 19-22
Author(s):  
Łukasz Bąk ◽  
Magdalena Bucior ◽  
Felix Stachowicz ◽  
Władysław Zielecki
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Shot Peening ◽  
Experimental Tests ◽  
Special Treatment ◽  
Surface Layers ◽  
Impact Bending ◽  
Improve Fatigue Strength ◽  
Compressive Residual Stresses ◽  
Improve Fatigue

Numerous investigations have been performed in an attempt to improve fatigue strength of materials by creating compressive residual stresses in the surface layers as a result of the shot peening process. For example, during exploitation of the separating screener, some parts of screen sieve plate situated near the fixed edge undergo the largest deformation caused by impact bending and need special treatment. In this paper, the results of experimental tests are presented to analyse the effect of micro shot peening on surface layer characteristics and fatigue strength of steel sheet specimens. The effect of shot peening is more visible when fatigue life is taking into account. Thus, the use of shot peening of sheet surface made it possible to increase fatigue life of screener sieve.

Fatigue Life Improvement of Welded Elements and Structures by Ultrasonic Impact Treatment

2011 ◽  
Author(s):  
Yuriy Kudryavtsev ◽  
Jacob Kleiman
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Fatigue Testing ◽  
Highway Bridges ◽  
Surface Layers ◽  
Ultrasonic Impact Treatment ◽  
Stress Relieving ◽  
Life Improvement

The ultrasonic impact treatment (UIT) is relatively new and promising process for fatigue life improvement of welded elements and structures. In most industrial applications this process is known as ultrasonic peening (UP). The beneficial effect of UIT/UP is achieved mainly by relieving of harmful tensile residual stresses and introducing of compressive residual stresses into surface layers of a material, decreasing of stress concentration in weld toe zones and enhancement of mechanical properties of the surface layers of the material. The UP technique is based on the combined effect of high frequency impacts of special strikers and ultrasonic oscillations in treated material. Fatigue testing of welded specimens showed that UP is the most efficient improvement treatment as compared with traditional techniques such as grinding, TIG-dressing, heat treatment, hammer peening and application of LTT electrodes. The developed computerized complex for UP was successfully applied for increasing the fatigue life and corrosion resistance of welded elements, elimination of distortions caused by welding and other technological processes, residual stress relieving, increasing of the hardness of the surface of materials. The UP could be effectively applied for fatigue life improvement during manufacturing, rehabilitation and repair of welded elements and structures. The areas/industries where the UP process was applied successfully include: Shipbuilding, Railway and Highway Bridges, Construction Equipment, Mining, Automotive, Aerospace. The results of fatigue testing of welded elements in as-welded condition and after application of UP are considered in this paper. It is shown that UP is the most effective and economic technique for increasing of fatigue strength of welded elements in materials of different strength. These results also show a strong tendency of increasing of fatigue strength of welded elements after application of UP with the increase in mechanical properties of the material used.

High Pressure and Flow Rate Measurements on Peroxide Dosing Pumps Under Laboratory and Site Conditions

2006 ◽  
Author(s):  
Franz H. Trieb ◽  
Reinhard Karl ◽  
Rene Moderer
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Research Work ◽  
Maximum Pressure ◽  
Hydraulic Pressure ◽  
Site Conditions ◽  
High Pressure Cylinder ◽  
Injection Pump ◽  
Pressure Cylinder ◽  
High Pressure Level

The performance and reliability of peroxide dosing pumps are essential for every LDPE plant. The paper presents the results of measurement at an initiator injection pump under laboratory and site conditions. The recording was done with a flow meter and a high pressure transducer, both suitable for a maximum pressure of 400 MPa. It compares the results of hydraulic pressure inside the actuating cylinder at the intensifier with high pressure level and flow rate on the discharge connection of the pump. Direct measurement inside the high pressure cylinder and the possibilities to influence the fluctuations with a servo valve system round out the research work.

scholarly journals Specific Features of the Replacement of the Available Flow Path by the Optimal Flow Path when Upgrading the Steam Turbine High-Pressure Cylinder

2021 ◽  
pp. 5-11
Author(s):  
Riza Sherfedinov ◽  
Oleksandr Usatyi ◽  
Olena Avdieieva ◽  
Mykhailo Daludin ◽  
Illia Yenin
Keyword(s):  
High Pressure ◽  
Turbine Unit ◽  
Optimization Problem ◽  
Flow Path ◽  
Feed Water ◽  
High Pressure Cylinder ◽  
Efficient Operation ◽  
Thermal Circuit ◽  
Optimal Flow ◽  
Pressure Cylinder

This scientific paper gives the main research data obtained during the solution of the search problem to define optimal parameter values for the thermal circuit of the К-540-23.5 turbine unit that would provide the most efficient operation both for the optimal version of the high pressure cylinder (HPC) as part of the turbine unit and the turbine unit on the whole. The effect of the distribution of heat differences in the stages of the optimal flow part of the high pressure cylinder used by the К-540-23.5 turbine on the integral quality factors of the turbine unit has been assessed. The calculation studies of the thermal circuit of the turbine unit with the optimal flow section of the high-pressure cylinder showed that the temperature of the underheated feed water in the high pressure heater (HPH) arranged near the steam generator has the most critical effect on the power and economical efficiency of the high pressure cylinder and entire turbine unit. The two-criterion Pareto problem for the upgrading of the turbine unit was formulated and solved to define optimal underheating temperature values. Consideration was given to the two variants of the solution of the optimization problem for the feed water underheating temperature in the high pressure heater. Comparison and analysis of the two variants of solution for the two-criterion optimization problem showed the identity of the obtained data and it confirms the correctness of the problem formulation and the algorithms used for its solution.

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