Selection Criteria for Clad Materials to Use With a 316H Base Material for High Temperature Nuclear Reactor Cladded Components

2020 ◽  
Author(s):  
B. Barua ◽  
M. C. Messner ◽  
R. I. Jetter ◽  
T.-L. Sham
Keyword(s):  
High Temperature ◽  
Selection Criteria ◽  
Nuclear Reactor ◽  
Design Method ◽  
Base Material ◽  
Class A ◽  
Ratcheting Strain ◽  
Creep Fatigue ◽  
Work Supports

Abstract The clad selection criteria proposed in this work supports a design approach provided in [PVP2020-21469] for cladded component for high temperature nuclear service. The proposed design method guards the clad material against the creep-fatigue failure and ratcheting strain accumulation in elevated temperature nuclear service without the requirement of long-term material properties. However, it limits the type of clad materials that can be used with the existing Class A materials qualified for ASME Section III, Division 5 rules. The analysis approach and design rules allow the use of two types of clad materials — soft clads that creep much faster than the base material and hard clads that creep much slower and have higher yield stress than the base material. This work proposes selection criteria for such soft and hard clad materials to use with a Class A metallic alloy — austenitic steel 316H. The criteria are developed based on the effect of relative elastic modulus and creep rate on the long term stress redistribution between the 316H base and the clad material. The proposed clad selection criteria are applicable up to a design temperature of 750°C and for 1% to 10% thick cladding. The selection criteria are evaluated on two materials — nickel and a molybdenum based alloy TZM — categorizing them as soft or hard clad for 316H base material.

Development of Design Method for High Temperature Nuclear Reactor Cladded Components

2020 ◽  
Author(s):  
B. Barua ◽  
M. C. Messner ◽  
R. I. Jetter ◽  
T.-L. Sham
Keyword(s):  
High Temperature ◽  
Nuclear Reactor ◽  
Nuclear Reactors ◽  
Design Method ◽  
Base Material ◽  
Approximate Design ◽  
Design Rules ◽  
Corrosion Resistant ◽  
Class A

Abstract High temperature nuclear reactors plan to use highly corrosive coolant such as molten salts, molten lead, and lead-bismuth eutectic mixtures. The existing Class A metallic materials qualified in the ASME Section III, Division 5 rules for high temperature nuclear reactors are not ideal for resisting corrosion when exposed to these coolants. One option to overcome this limitation would be to Code-qualify new corrosion-resistant materials for Class A service, however this process is long and expensive and requires long-term creep test data. A near-term alternative would be to allow designers to clad the existing Class A base materials with non-qualified corrosion-resistant materials. However, there are currently no ASME design rules for cladded components to guard against creepfatigue failure and ratcheting strain accumulation in elevated temperature nuclear service. This work addresses this deficiency by proposing a design strategy for cladded components that does not require long-term testing of clad materials. The proposed approach relies on approximate design analysis methods for two types of clad materials — soft clad that creeps faster than the base material and hard clad that creeps slower and has higher yield stress than the base material. The proposed approach treats a soft clad material as perfectly compliant and a hard clad material as linear elastic. Sample finite element analyses of representative high temperature reactor components are performed to verify the approach. At the end, a complete set of design rules is provided for each of the two types of cladded components.

Design Methodologies for High Temperature Reactor Structural Components Cladded With Noncompliant Materials

2019 ◽  
Author(s):  
B. Barua ◽  
V.-T. Phan ◽  
M. C. Messner ◽  
B. Jetter ◽  
T.-L. Sham ◽  
...  
Keyword(s):  
High Temperature ◽  
Base Material ◽  
Design Rules ◽  
Corrosion Resistant ◽  
Class A ◽  
Creep Fatigue ◽  
The Difference ◽  
Near Term ◽  
Term Creep

Abstract The existing Class A metallic materials qualified for ASME Section III, Division 5 rules for high temperature nuclear reactors, are not optimized for corrosion resistance when exposed to corrosive reactor coolants such as molten salts, and molten lead and lead-bismuth eutectic. Introducing new corrosion-resistant materials into the Code would be a lengthy and expensive process for long design lifetimes, requiring long-term creep test data. A near-term alternative solution might be to allow designers to clad the existing Class A materials with thin layer of some corrosion-resistant material. However, the current ASME Section III, Division 5 rules provide no guidance on evaluating cladded components against the Code creep-fatigue or strain limits requirements. This necessitates the development of design rules for cladded components that do not require long-term testing of clad materials. Depending on the difference in mechanical properties, the influence of clad on the long term response of the structural system can be significant or negligible. This work focuses on developing design rules for cladded components with a clad material that does not accumulate significant inelastic deformation compared to the base material. This work proposes to treat such clad materials as linear elastic. Sample calculations including finite element analyses of a representative molten salt reactor heat exchanger tube without and with clad were performed to verify the proposed approach. Finally, a complete set of design rules for components with noncompliant clad material is proposed.

Development of Design Method for High Temperature Nuclear Reactor Cladded Components

2021 ◽  
Author(s):  
Bipul Barua ◽  
Mark C. Messner ◽  
Robert I. Jetter ◽  
T. L. Sham
Keyword(s):  
High Temperature ◽  
Nuclear Reactor ◽  
Design Method

SIE ASME-NH Program for the Structural Integrity Evaluations of a LMR Subjected to Elevated Temperature Operations

2006 ◽  
Author(s):  
Gyeong-Hoi Koo ◽  
Jae-Han Lee
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Structural Integrity ◽  
Creep Damage ◽  
Pressure Vessels ◽  
Step Size ◽  
Time Step ◽  
Time Step Size ◽  
Ratcheting Strain ◽  
Creep Fatigue

In this paper, SIE ASME-NH (Structural Integrity Evaluation by ASME-NH) program, which has a computerized implementation of the details for ASME Pressure Vessels and Piping Code Section III Subsection NH rules including the time-dependent primary stress limits, total accumulated creep ratcheting strain limits, and the creep-fatigue limits for the reactor structures subjected to elevated temperature operations, are described with their detailed application procedures. Using this code, the selected high temperature structures which are subjected to two cycle types are evaluated and the sensitivity studies for the effects of the time step size, primary load, numbers of a cycle, normal temperature on the creep damage evaluations and the effects of the load history on the creep ratcheting strain calculations are investigated. From the selected applications, it is verified that the developed SIE ASME-NH Program is an easy user interface program and it can be an effective tool for the high temperature structural integrity evaluations of LMR.

Acceptance Criteria for the Mechanical Integrity of Clad/Base Metal Interface for High Temperature Nuclear Reactor Cladded Components

2020 ◽  
Author(s):  
B. Barua ◽  
M. C. Messner ◽  
A. Rovinelli ◽  
T.-L. Sham
Keyword(s):  
Shear Stress ◽  
Selection Criteria ◽  
Design Method ◽  
Temperature Cycling ◽  
Metal Interface ◽  
Interface Shear ◽  
Interface Shear Stress ◽  
Class A ◽  
Design Life ◽  
Near Term

Abstract The existing Class A metallic materials qualified in the ASME Section III, Division 5 rules for high temperature nuclear reactors do not have optimal corrosion resistance for some reactor coolants such as liquid lead, lead/bismuth eutectic, and molten salts which is a major constraint on long life designs. A near term solution to this limitation is the use of cladded components — overlay the Class A materials with a thin layer of some corrosion resistant material. However, this necessitates the development of a design method for cladded components without requiring long-term testing of clad materials in order to support the near-term deployment of these advanced reactor systems. In two other PVP papers [PVP2020-21469, PVP2020-21493], the development of such design method along with a complete set of design rules and clad selection criteria are presented. However, the developed design rules and clad selection criteria are based on a priori assumption of perfect bonding between the clad and base materials. In practice the clad/base debonding may occur before the end of the design life of the component. Therefore, this paper focuses on developing a general acceptance test for checking whether the mechanical integrity of the clad/ base metal interface will be retained till the end of the design life. This work proposes to perform temperature cycling tests on cladded buttons of 12.7 mm diameter and a few mm thickness. A simple analytical expression is provided to determine the temperature range for the temperature cycling tests so that the clad/base interface shear stress intensity at the edge of the cladded button mimics the maximum interface shear stress intensity experienced by the component during the design transients. The paper also provides a method to determine the clad/base interfacial shear stress from finite element structural analysis of components.

High Temperature Creep-Fatigue Design and Service Experience

2008 ◽  
Vol 1125 ◽  
Author(s):  
A-A. F. Tavassoli ◽  
B. Fournier ◽  
M. Sauzay
Keyword(s):  
High Temperature ◽  
Austenitic Stainless Steels ◽  
Oxide Dispersion Strengthened ◽  
Cyclic Softening ◽  
Fatigue Tests ◽  
Oxide Dispersion ◽  
Martensitic Steels ◽  
Fatigue Design ◽  
Creep Fatigue

ABSTRACTGeneration IV fission and future fusion reactors envisage development of more efficient high temperature concepts where materials performances under creep-fatigue hold the key to success. This paper presents extended experimental results obtained from creep, fatigue and creep-fatigue tests on the main structural materials retained for these concepts, namely: stainless steel type 316L(N), the conventional Modified 9Cr-1Mo martensitic steel and its low activation derivatives such as Eurofer steel, and their more advanced grades strengthened by oxide dispersion. It shows that the existing recommendations made in design codes adequately cover individual damage due to creep or fatigue but often fall short under combined creep-fatigue interaction. This is partly due to the difficulties of reproducing service conditions in laboratory. In this paper, results from tests performed on components removed from reactor, after long service, are used to refine code recommendations.Using the above combined assessment, it is concluded that there is good confidence in predicting creep-fatigue damage for austenitic stainless steels. For the martensitic steels the effects of cyclic softening and microstructure coarsening throughout the fatigue life need more consideration in creep-fatigue recommendation. In the long-term development of ferritic/martensitic oxide dispersion strengthened grades with stable microstructure and no cyclic softening, appears promising provided problems associated with their fabrication and embrittlement are resolved.

Healing of Pores in Metals by Magnetic Pressure Pulses

1990 ◽  
Vol 195 ◽  
Author(s):  
V.I. Betedhtin ◽  
A.B. Pakhomov ◽  
B.P. Peregood ◽  
A.I. Petrov ◽  
M. V. Razuvaeva
Keyword(s):  
Mechanical Properties ◽  
Magnetic Properties ◽  
Temperature Field ◽  
High Temperature ◽  
Surface Deformation ◽  
Physical And Mechanical Properties ◽  
Magnetic Pressure ◽  
High Temperature Creep ◽  
Creep Fatigue

The problem of healing of microscopic pores and cracks in the temperature field and understatic and dynamic pressures attracts considerable attention. Indeed, regeneration of continuity leads to a significant improvement of physical and mechanical properties of the materials where micropores were formed as a result of long—term loading (high—temperature creep, fatigue), surface deformation (friction, wear, grinding), specialconditions of processing (casting, powder metallurgy, condensed films) [1– 10]. For instance, the elimination of porosity allows longer lifetimes [1– 7] and higher ultimate strength [8], elastioonstants [91], and also electric and magnetic properties [10]to be achieved.

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