Measurement of Through-Thickness Residual Stresses Under Restrained Condition in Pressure Vessel Steel Weld

2021 ◽  
pp. 119-125
Author(s):  
P. K. Taraphdar ◽  
M. M. Mahapatra ◽  
A. K. Pradhan ◽  
P. K. Singh ◽  
Kamal Sharma ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Pressure Vessel ◽  
Pressure Vessel Steel ◽  
Steel Weld ◽  
Vessel Steel ◽  
Restrained Condition

Mechanisms and Modeling Comparing HB7 and A723 High Strength Pressure Vessel Steels

2004 ◽  
Vol 126 (4) ◽  
pp. 473-477 ◽  
Author(s):  
E. Troiano ◽  
A. P. Parker ◽  
J. H. Underwood
Keyword(s):  
Residual Stresses ◽  
Pressure Vessel ◽  
High Strength ◽  
Strength Level ◽  
Fatigue Properties ◽  
Pressure Vessel Steel ◽  
Cracking Resistance ◽  
Vessel Steel ◽  
Design Engineers ◽  
Vessel Material

HB7, an ultra-clean, high strength pressure vessel steel manufactured in France, is compared to A723 steel. This steel, suggested as an improved pressure vessel material is currently being proposed for critical applications, and will likely be used more frequently as design engineers discover its capabilities. This paper includes comparisons of strength, fracture toughness, fatigue properties and composition of the two steels, followed by an in-depth comparison and modeling of environmental cracking resistance, Bauschinger-modified residual stresses and fatigue lives. Results indicate that in all critical areas, with the exception of Bauschinger-reduced residual stress, the HB7 is superior to the A723 steel. Particularly for small amounts of autofrettage, near-bore residual stresses are reduced for HB7 steel compared to those for A723 steel at the same strength level. The greatest improvement of the HB7 over the A723 is in environmental cracking resistance. The HB7, when tested in concentrated sulfuric acid, exhibits five orders of magnitude longer crack incubation times and three orders of magnitude slower crack growth rates, when compared to A723 steel at the same strength level.

CHARACTERIZATION OF IRRADIATED A533B PRESSURE VESSEL STEEL WELD

1987 ◽  
Vol 48 (C6) ◽  
pp. C6-429-C6-434
Author(s):  
M. K. Miller ◽  
M. G. Burke
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessel Steel ◽  
Steel Weld ◽  
Vessel Steel

Development of Simplified Empirical Phase Transformation Model for Use in Welding Residual Stress Simulations

2014 ◽  
Author(s):  
Nicholas O’Meara ◽  
John A. Francis ◽  
Simon D. Smith ◽  
Philip J. Withers
Keyword(s):  
Thermal Expansion ◽  
Residual Stresses ◽  
Phase Transformations ◽  
Pressure Vessel ◽  
Welding Residual Stress ◽  
Transformation Model ◽  
Pressure Vessel Steel ◽  
Vessel Steel ◽  
Fe Simulations ◽  
Wide Range

The level and distribution of residual stresses in welds arises from the complex thermo-mechanical history of heat flow and thermal expansion at very high temperatures. It is not possible to make assessments of these with the methods that are used to determine service stresses. Simulation techniques have been developed over many years making it increasingly possible to predict residual stresses. These models need accurate materials data including, where applicable, the effect of phase transformations. In nuclear reactor pressure vessel welds, it is necessary to consider welding as a metallurgical problem as well as a thermo-mechanical one and FE simulations of these require a wide range of material data in order to create suitable input parameters. It is crucial that models of ferritic steel welds simulate the effects of phase transformations because the different phases have different thermal expansion coefficients. Partly due to differences in thermal expansion coefficient attributed to the different phases, but more significantly because of the associated transformation strain and transformation plasticity. Further to this, predicting the distribution of the phase fractions enables structural simulations to account for the distribution of mechanical properties throughout a weld. In this work, a simplified approach to producing an empirical model to simulate phase transformations in SA-508 Gr3 pressure vessel steel is presented. A commercial finite element package is used to implement the model which calculates the volume fraction of bainite, martensite and austenite and the thermal strains that evolve over the thermal excursions. The results of these FE simulations are compared to experimental data.

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