Investigation of the Influence of Improvement on the Effect of Strain hardening of 34CrMo4 in the Production of Seamless Steel Pressure Vessels from Pipes

2015 ◽  
pp. 197-205
Author(s):  
V. Marušić ◽  
I. Lacković ◽  
L. Marušić
Keyword(s):  
Strain Hardening ◽  
Pressure Vessels ◽  
Seamless Steel

scholarly journals Thermal-Stress Ratchet Mechanism in Pressure Vessels

1959 ◽  
Vol 81 (2) ◽  
pp. 190-194 ◽  
Author(s):  
D. R. Miller
Keyword(s):  
Growth Rate ◽  
Thermal Stress ◽  
Internal Pressure ◽  
Strain Hardening ◽  
Thermal Stresses ◽  
Pressure Vessels ◽  
Progressive Reduction ◽  
Ratchet Mechanism

The combination of cyclic thermal stresses and sustained internal pressure in a vessel is shown to be a source of progressive expansion of the vessel if the stresses are sufficiently high. Criteria presented allow determination of limits to be imposed on stresses in order to prevent progressive expansion or to allow estimation of the expansion per cycle where stresses are sufficient to produce growth. The effect of strain-hardening of the metal on progressive reduction of the growth rate is discussed.

The Collapse or Ballooning Pressure of Thick-Walled Pressure Vessels

1983 ◽  
Vol 22 ◽  
Author(s):  
B. Crossland
Keyword(s):  
Mild Steel ◽  
Strain Hardening ◽  
Pressure Vessel ◽  
Factor Of Safety ◽  
Plastic Material ◽  
Pressure Vessels ◽  
Bursting Pressure ◽  
Collapse Pressure ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

ABSTRACTDiscussion of the proposed extension of the ASME pressure vessel code to cover operating pressures up to 1.4 GPa (200000 lbf/in2 ) has generated the proposal that two criteria should be used, of which one would be the collapse or ballooning pressure not the bursting pressure. The present paper examines this proposal in relation to extensive data on the collapse and bursting of thick-walled vessels available to the author.It is concluded that the collapse pressure is only readily calculable for materials which approach the behaviour of an elastic/perfectly plastic material. It also appears for materials with significant strain hardening characteristics, such as mild steel, that the collapse pressure considerably underestimates the bursting pressure, whereas for a material which behaves as an elastic/perfectly plastic material the collapse pressure is nearly coincident with the bursting pressure. Consequently if the collapse pressure was adopted and if the factor of safety against collapse was adequate for one material it might be more or less than adequate for another material, which would appear to be unacceptable.

Elastic-Plastic Stress Analysis of Pressure Vessels

2012 ◽  
Author(s):  
Yang-chun Deng ◽  
Gang Chen
Keyword(s):  
Internal Pressure ◽  
Stress Analysis ◽  
Strain Hardening ◽  
Pressure Vessel ◽  
Plastic Instability ◽  
Pressure Vessels ◽  
Structural Deformation ◽  
Elastic Plastic ◽  
Thin Walled ◽  
Plastic Stress

To save material, the safety factor of pressure vessel design standards is gradually decreased from 5.0 to 2.4 in ASME Boiler and Pressure Vessel Codes. So the design methods of pressure vessel should be more rationalized. Considering effects of material strain hardening and non-linear structural deformation, the elastic-plastic stress analysis is the most suitable for pressure vessels design at present. This paper is based on elastic-plastic theory and considers material strain hardening and structural deformation effects. Elastic-plastic stress analyses of pressure vessels are summarized. Firstly, expressions of load and structural deformation relationship were introduced for thin-walled cylindrical and spherical vessels under internal pressure. Secondly, the plastic instability for thin-walled cylindrical and spherical vessels under internal pressure were analysed. Thirdly, to prevent pressure vessels from local failure, the ductile fracture strain of materials was discussed.

Shakedown Loads for Pressure Vessels of Strain Hardening Materials

1969 ◽  
Vol 11 (3) ◽  
pp. 340-342 ◽  
Author(s):  
T. E. Taylor
Keyword(s):  
Strain Hardening ◽  
Power Law ◽  
Pressure Vessels ◽  
Strain Hardening Exponent ◽  
Rigid Plastic ◽  
Linear Elastic ◽  
Perfectly Plastic ◽  
Creep Analysis ◽  
Family Of Curves ◽  
The Relationship

A power law, well known in creep analysis, embodies a family of curves which express the stress-strain relations for a family of materials ranging from linear elastic to rigid perfectly plastic. A linearization of the relationship between stress concentration factor and the reciprocal of strain hardening exponent for geometrically similar pressure vessels made of materials within the family has enabled a view of shakedown in vessels of strain hardening materials to be formulated. The absence of discontinuities in the power law, except at the rigid plastic end point, results in shakedown loads dependent on strain hardening exponent and previous loading history.

Fatigue Life of Seamless Steel Pressure Vessels

1987 ◽  
Vol 109 (3) ◽  
pp. 323-328
Author(s):  
R. L. Brockenbrough
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fracture Mechanics ◽  
Strain Gage ◽  
Fatigue Tests ◽  
Pressure Vessels ◽  
Finite Element Models ◽  
Conservative Estimate ◽  
Cyclic Pressure ◽  
Seamless Steel

Cyclic-pressure fatigue tests of three seamless steel pressure vessels show that typical production vessels should have a fatigue life at least equal to the allowable life calculated by code procedures. Stresses from finite-element models and strain-gage measurements are correlated and used in a simplified fracture mechanics approach for a conservative estimate of fatigue life.

Plastic Instability Pressure of Conical Shells

2011 ◽  
Author(s):  
R. Adibi-Asl
Keyword(s):  
Strain Hardening ◽  
Large Deformation ◽  
Applied Load ◽  
Failure Modes ◽  
Plastic Instability ◽  
Pressure Vessels ◽  
Conical Shells ◽  
Hardening Curve ◽  
Dimensional Instability ◽  
Analytical Expressions

There several failure modes that are considered in the available codes and standards in field of pressure vessel and piping. One of these failure modes is plastic instability. This failure mode is defined as the pressure for which the components/structures approach dimensional instability (large deformation), i.e. unbounded displacement for a small increment in the applied load. In order to find this pressure both large deformation and strain hardening curve are considered. When the slope of numerically generated load-deformation curve approaching zero the corresponding applied load is considered as plastic instability load. Unlike cylindrical and spherical pressure vessels, available theoretical solution in range of plastic instability load for conical shells are very limited. Hence, it would be very useful to predict the behavior of these components with acceptable accuracy for design purposes. Analytical expressions are derived to determined plastic instability load of s conical shell subjected to internal pressure and when it is subjected to hydrostatic pressure (i.e., storage tanks). The geometrical changes can be estimated using the proposed solutions when considering the material strain hardening curve.

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