Use of Duplex Stainless Steel in Economic Design of a Pressure Vessel

2006 ◽  
Vol 129 (1) ◽  
pp. 155-161 ◽  
Author(s):  
Milan Veljkovic ◽  
Jonas Gozzi

Pressure vessels have been used for a long time in various applications in oil, chemical, nuclear, and power industries. Although high-strength steels have been available in the last three decades, there are still some provisions in design codes that preclude a full exploitation of its properties. This was recognized by the European Equipment Industry and an initiative to improve economy and safe use of high-strength steels in the pressure vessel design was expressed in the evaluation report (Szusdziara, S., and McAllista, S., EPERC Report No. (97)005, Nov. 11, 1997). Duplex stainless steel (DSS) has a mixed structure which consists of ferrite and austenite stainless steels, with austenite between 40% and 60%. The current version of the European standard for unfired pressure vessels EN 13445:2002 contains an innovative design procedure based on Finite Element Analysis (FEA), called Design by Analysis-Direct Route (DBA-DR). According to EN 13445:2002 duplex stainless steels should be designed as a ferritic stainless steels. Such statement seems to penalize the DSS grades for the use in unfired pressure vessels (Bocquet, P., and Hukelmann, F., 2001, EPERC Bulletin, No. 5). The aim of this paper is to present an investigation performed by Luleå University of Technology within the ECOPRESS project (2000-2003) (http://www.ecopress.org), indicating possibilities towards economic design of pressure vessels made of the EN 1.4462, designation according to the European standard EN 10088-1 Stainless steels. The results show that FEA with von Mises yield criterion and isotropic hardening describe the material behaviour with a good agreement compared to tests and that 5% principal strain limit is too low and 12% is more appropriate.

1970 ◽  
Vol 92 (1) ◽  
pp. 11-16 ◽  
Author(s):  
J. M. Barsom ◽  
S. T. Rolfe

Increasing use of high-strength steels in pressure-vessel design has resulted from emphasis on decreasing the weight of pressure vessels for certain applications. To demonstrate the suitability of a 140-ksi yield strength steel for use in unwelded pressure vessels, HY-140(T)—a quenched and tempered 5Ni-Cr-Mo-V steel—was fabricated and subjected to various burst and fatigue tests, as well as to various laboratory tests. In general, results of the investigation indicated very good tensile, Charpy, Nil Ductility Transition Temperature (NDT), low-cycle fatigue, and stress-corrosion properties of HY-140(T) steels, as well as very good burst tests results, in comparison with existing high-yield strength pressure-vessel steels. The results also indicate that the HY-140(T) steel should be an excellent material for its originally designed purpose, Naval hull applications.


Author(s):  
Sumit Banerjee

Abstract: Duplex Stainless Steel was developed long back in 1930 and gradually finds its wide application because of its high strength, good weldability, good toughness and resistance to stress corrosion cracking. This alloy finds its application in pressure vessels, bridges, process plants and also in typically down to minus 50 degree centigrade applications. However, because of its high alloy content thermal conductivities of duplex stainless steel are low. Casting this alloy is difficult and can be industrially used after proper heat treatment. In this present study corrosion rates were measured for CD4MCu in terms of weight loss/unit area/hour and microstructures were observed in different corrosive medium with time as variable.


2000 ◽  
Vol 6 (S2) ◽  
pp. 766-767
Author(s):  
O. A. Hilders ◽  
L. Sáenz ◽  
N. Peña ◽  
M. Ramos ◽  
A. Quintero ◽  
...  

Due to the very good combination of the most outstanding properties of ferrite and austenite, the microstructure of duplex stainless steels allows them to obtain high strength and toughness levels even at low temperatures . As a result of these combined effects, duplex stainless steels have become very popular for many applications . In practice, the prolonged use of these materials at temperatures below approximately 500°C may cause an embrittlement of the ferrite phase, which has been called 475°C embrittlement. Thus, the isothermal aging at 475°C can be exploited to produce a variety of strength values associated with the corresponding decreases in ductility and variations of the fractal dimension of the fracture surfaces. No experimental measurements of the fractal dimension - tensile properties relationships are available for many commercial metallic alloys, then, the present experiments on a duplex stainless steel were conducted to show that the fractal dimension, D, many be used as a characterization parameter in fracture morphology - mechanical properties studies.


Author(s):  
Feng Gui ◽  
Ramgopal Thodla ◽  
Ken Evans ◽  
Carlos Joia ◽  
Ilson Palmieri Baptista

Corrosion fatigue performance is of interest for high strength steels in riser applications. This work investigated the corrosion fatigue performance of 2507 duplex stainless steel for use as riser materials in environments containing high partial pressures of carbon dioxide (50–100 bar) and limited quantity of hydrogen sulfide (0–0.12 bar). The procedures developed for controlling oxygen and Fe2+ contamination as well as methods to evaluate the concentration of H2S in the autoclave are presented. The crack growth rates and ΔKth for these materials in the pressure environments were discussed along with procedures to obtain ΔKth, when they were below 5ksi√in. Low crack growth rates in the range of 1×10−8 in/cycle were measured and the effect of sour environments was quantified. The fatigue crack growth rate in sour environments on 2507 duplex stainless steel is a 10x higher than in air.


Author(s):  
Alison N. O’Connor ◽  
Catrin M. Davies ◽  
Stephen J. Garwood ◽  
Isabel Hadley

Abstract The structural integrity of pressure vessels (PVs) is controlled by the application of various design and fabrication codes and standards. Within the European single market (ESM) design codes exist at both a European and a national level which can lead to variability in design procedures. The European standard EN 13445 has been updated several times to modify the design curves based on analytical modelling of high strength materials. The design curves in EN 13445 now differ significantly from those presented in the British national code that preceded it, namely PD 5500. As a result higher minimum Charpy test temperatures (T27J) are found using the EN 13445 procedure in comparison to those derived using the PD 5500 procedure. While the PD 5500 design curves have been validated experimentally it is generally accepted that they are overly conservative. This inherent conservatism in PD 5500 may account for some of the differences in the minimum Charpy test temperature, the analytical model used to generate the EN 13445 design curves however was validated with data from high strength steels only (σy ≥ 420 MPa). It is not clear that the results can be applied directly to low/medium strength materials. This work identifies some of the disparities between the EN 13445 and PD 5500 procedures, for low temperature applications. A programme of work, at Imperial College London, is described. This programme of work, currently underway, is aimed at addressing concerns about the robustness of the updated EN 13445 design curves, especially for lower-strength steels in the as-welded condition.


Alloy Digest ◽  
1981 ◽  
Vol 30 (7) ◽  

Abstract AISI No. 633 is a chromium-nickel-molybdenum stainless steel whose properties can be changed by heat treatment. It bridges the gap between the austenitic and martensitic stainless steels; that is, it has some of the properties of each. Its uses include high-strength structural applications, corrosion-resistant springs and knife blades. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-389. Producer or source: Stainless steel mills.


Alloy Digest ◽  
2009 ◽  
Vol 58 (5) ◽  

Abstract Crucible 174 SXR is a premium-quality precipitation-hardening stainless steel designed for use as rifle barrels. It is a modification of Crucible’s 17Cr-4Ni that offers substantially improved machinability without sacrificing toughness. Its excellent corrosion resistance approaches that of a 300 series austenitic stainless steel, while its high strength is characteristic of 400 series martensitic stainless steels. At similar hardness levels, Crucible 174 SXR offers greater toughness than either the 410 or 416 stainless steels which are commonly used for rifle barrels. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming and heat treating. Filing Code: SS-1034. Producer or source: Crucible Service Centers.


Author(s):  
Waris N Khan ◽  
Rahul Chhibber

This work investigates the microstructure and mechanical properties of 2507 super duplex stainless steel and API X70 high strength low alloy steel weld joint. This joint finds application in offshore hydrocarbon drilling riser and oil–gas pipelines. Coated shielded metal arc welding electrodes have been designed and extruded on 309L filler and their performance compared with a commercial austenitic electrode E309L. Filler 309L solidifies in ferrite-austenite (F-A) mode with a resultant microstructure comprising skeletal ferrites with austenite distributed in the interdendritic region. Results of tensile and impact tests indicate that weld fabricated with laboratory-developed electrodes has higher ductility and impact energy than the commercial electrode. The tensile strength and weld hardness of commercial electrodes are superior. The laboratory-made electrode’s microhardness is lower than the commercial electrodes, making the former less prone to failure. An alternative welding electrode coating composition has been suggested through this work and found to be performing satisfactorily and comparable to the commercially available electrodes.


2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Gongfeng Jiang ◽  
Gang Chen ◽  
Liang Sun ◽  
Yiliang Zhang ◽  
Xiaoliang Jia ◽  
...  

Experimental results of uniaxial ratcheting tests for stainless steel 304 (SS304) under stress-controlled condition at room temperature showed that the elastic domain defined in this paper expands with accumulation of plastic strain. Both ratcheting strain and viscoplastic strain rates reduce with the increase of elastic domain, and the total strain will be saturated finally. If the saturated strain and corresponded peak stress of different experimental results under the stress ratio R ≥ 0 are plotted, a curve demonstrating the material shakedown states of SS304 can be constituted. Using this curve, the accumulated strain in a pressure vessel subjected to cyclic internal pressure can be determined by only an elastic-plastic analysis, and without the cycle-by-cycle analysis. Meanwhile, a physical experiment of a thin-walled pressure vessel subjected to cyclic internal pressure has been carried out to verify the feasibility and effectiveness of this noncyclic method. By comparison, the accumulated strains evaluated by the noncyclic method agreed well with those obtained from the experiments. The noncyclic method is simpler and more practical than the cycle-by-cycle method for engineering design.


Sign in / Sign up

Export Citation Format

Share Document