Life Prediction of Stainless Steels under Creep-Fatigue

2009 ◽  
Vol 413-414 ◽  
pp. 725-732 ◽  
Author(s):  
Xiao Cong He
Keyword(s):  
Stainless Steel ◽  
Elevated Temperature ◽  
Test Data ◽  
Stainless Steels ◽  
Life Prediction ◽  
Prediction Models ◽  
Fatigue Behavior ◽  
Summation Method ◽  
Tensile Creep ◽  
Creep Fatigue

The aim of this study is to investigate the creep-fatigue behavior of stainless steel materials. Based on the elevated-temperature tensile, creep and rupture test data, thermal creep-fatigue modelling was conducted to predict the failure life of stainless steels. In the low cycle thermal fatigue life model, Manson’s Universal Slopes equation was used as an empirical correlation which relates fatigue endurance to tensile properties. Fatigue test data were used in conjunction with different modes to establish the relationship between temperature and other parameters. Then creep models were created for stainless steel materials. In order to correlate the results of short-time elevated temperature tests with long-term service performance at more moderate temperatures, different creep prediction models, namely Basquin model, Sherby-Dorn model and Manson-Haferd model, were studied. Comparison between the different creep prediction models were carried out for a range of stresses and temperatures. A linear damage summation method was used to establish life prediction model of stainless steel materials under creep-fatigue.

Sensitivity Study on Parameters for Fatigue-Creep Modeling of Stainless Steel Materials

2012 ◽  
Vol 628 ◽  
pp. 217-220
Author(s):  
Xiao Cong He
Keyword(s):  
Stainless Steel ◽  
Prediction Models ◽  
Strain Range ◽  
Sensitivity Study ◽  
Summation Method ◽  
Creep Model ◽  
Fatigue Life Estimation ◽  
Creep Fatigue ◽  
Fatigue Endurance

In present paper, sensitivity study on parameters for fatigue-creep model of stainless steel materials has been carried out. An analytical model has been established to predict fatigue-creep life of AISI347 stainless steel. Manson’s Universal Slopes equation has been used as an empirical correlation which relates fatigue endurance to tensile properties. Different creep prediction models have been studied in order to correlate the results of shout-time elevated temperature tests with long-term service performance at more moderate temperatures. Comparison between the different creep prediction models and experimental results were carried out for a range of stresses and temperatures. A linear damage summation method has been used to combined fatigue and creep. The results of sensitivity analysis indicate that strain range and temperature have very significant influence on creep-fatigue life estimation.

UNILOY 430

Alloy Digest ◽  
1982 ◽  
Vol 31 (5) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Elevated Temperature ◽  
Stainless Steels ◽  
Heat Treating ◽  
Storage Tanks ◽  
Good Resistance ◽  
Temperature Performance ◽  
Temperature Scaling

Abstract UNILOY 430 is a medium-chromium (17%) non-hardening, ferritic stainless steel. Of the AISI 400 series stainless steels, Uniloy 430 most nearly resembles the 18% chromium-8% nickel stainless steels in fabrication and service. It has excellent resistance to corrosion and good resistance to elevated-temperature scaling. Its many uses include architectural trim, nitric acid storage tanks and kitchen appliances. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-408. Producer or source: Cyclops.

LOW CYCLE FATIGUE BEHAVIOR AND LIFE PREDICTION OF A CAST COBALT-BASED SUPERALLOY

2012 ◽  
Vol 06 ◽  
pp. 251-256
Author(s):  
HO-YOUNG YANG ◽  
JAE-HOON KIM ◽  
KEUN-BONG YOO
Keyword(s):  
Fatigue Life ◽  
Strain Energy ◽  
Life Prediction ◽  
Prediction Models ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Total Strain ◽  
Cycle Fatigue ◽  
Total Strain Range ◽  
Different Temperatures

Co -base superalloys have been applied in the stationary components of gas turbine owing to their excellent high temperature properties. Low cycle fatigue data on ECY-768 reported in a companion paper were used to evaluate fatigue life prediction models. In this study, low cycle fatigue tests are performed as the variables of total strain range and temperatures. The relations between plastic and total strain energy densities and number of cycles to failure are examined in order to predict the low cycle fatigue life of Cobalt-based super alloy at different temperatures. The fatigue lives is evaluated using predicted by Coffin-Manson method and strain energy methods is compared with the measured fatigue lives at different temperatures. The microstructure observing was performed for how affect able to low-cycle fatigue life by increasing the temperature.

scholarly journals Rapid fatigue life prediction for spot-welded joint of SUS301 L-DLT stainless steel and Q235B carbon steel based on energy dissipation

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881101 ◽  
Author(s):  
Yaliang Liu ◽  
Yibo Sun ◽  
Yang Sun ◽  
Hongji Xu ◽  
Xinhua Yang
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Energy Dissipation ◽  
Life Prediction ◽  
Welded Joint ◽  
Fatigue Behavior ◽  
Dissimilar Materials ◽  
Fatigue Life Prediction ◽  
Spot Welded

Spot welding of dissimilar materials can utilize the respective advantage comprehensively, of which reliable prediction of fatigue life is the key issue in the structure design and service process. Taking into account almost all the complex factors that have effects on the fatigue behavior such as load level, thickness, welding nugget diameter, vibrational frequency, and material properties, this article proposed an energy dissipation-based method that is able to predict the fatigue life for spot-welded dissimilar materials rapidly. In order to obtain the temperature gradient, the temperature variations of four-group spot-welded joint of SUS301 L-DLT stainless steel and Q235 carbon steel during high-cycle fatigue tests were monitored by thermal infrared scanner. Specifically, temperature variation disciplines of specimen surface were divided into four stages: temperature increase, temperature decrease, continuous steady increase in temperature, and ultimate drop after the fracture. The material constant C that a spot-welded joint of dissimilar material needs to reach fracture is 0.05425°C·mm3. When the specimen was applied higher than the fatigue limit, the highest error between experimental values and predicted values is 18.90%, and others are lower than 10%. Therefore, a good agreement was achieved in fatigue life prediction between the new method and the validation test results.

On the Development of Physically Based Life Prediction Models in the Thermo Mechanical Fatigue of Ni-Base Superalloys

2011 ◽  
Vol 465 ◽  
pp. 47-54 ◽  
Author(s):  
Stephen D. Antolovich ◽  
Robert L. Amaro ◽  
Richard W. Neu ◽  
A Staroselsky
Keyword(s):  
High Temperature ◽  
Damage Evolution ◽  
Life Prediction ◽  
Prediction Models ◽  
High Temperature Fatigue ◽  
Mechanical Fatigue ◽  
Use Of Resources ◽  
Physically Based ◽  
Creep Fatigue ◽  
Materials Used

In a world increasingly concerned with environmental factors and efficient use of resources, increasing operating temperatures of high temperature machinery can play an important role in meeting these goals. In addition, the cost of failure of such devices is rapidly becoming prohibitive. For example, in an airline crash airframe and engine manufacturers are, on average, held liable for 1,000,000 euros per fatality excluding the loss of property. Thus there is considerable pressure to make machinery that can operate much more safely at high temperatures. This means that the old ways of guarding against high temperature fatigue failure (e.g. factor of safety, S/N curves, creep life) are no longer acceptable; more reliable, accurate, and efficient means are needed to manage life, durability and risk. In this paper, high temperature fatigue is considered in terms of past successes and current challenges. Particular emphasis is placed on understanding damage mechanisms and their interactions both in terms of scientific interest and technological importance. Materials used in nuclear reactors (e.g. selected steels and solid solution Ni-base alloys) and in hot sections of jet engines (e.g. superalloys) are used as vehicles to illustrate damage evolution and interaction. Phenomenological life prediction models are presented and compared with physics-based damage evolution/interaction models which are based on observed physical processes such as creep/fatigue/environment interactions. It is shown that in many cases, in spite of the emphasis on creep-fatigue interactions, the most damaging forms of damage that occur under thermo-mechanical fatigue (TMF) loading result from the interaction of slip bands with oxidized boundaries.

Applicability of Solid Lubricant Coatings in Cold Rod Extrusion of Stainless Steels

2020 ◽  
Vol 404 ◽  
pp. 95-100
Author(s):  
Andreas Jobst ◽  
Marion Merklein
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Work Hardening ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Equivalent Plastic Strain ◽  
Grain Structure ◽  
Cold Extrusion ◽  
Operating Characteristics ◽  
Lubricant Coating

Cold extrusion is an established technology for the production of dimensionally accurate components in large series. Due to the high material and energy efficiency, a resource-saving manufacturing of high-performance parts is possible. Forming at room temperature leads to an advantageous grain structure and work hardening of the material, resulting in components with favorable operating characteristics. Nevertheless, a challenge is the generation of residual stresses during forming, which are influencing the fatigue behavior. The modification of the tribological conditions is one method for influencing the parts’ residual stress state. However, the high strength and work hardening of the materials formed at room temperature leads to high tribological loads between billet and die. These challenges are intensified by the increasing use of stainless steels due to growing demands for corrosion resistant components. The aim followed within this paper is therefore to investigate the applicability of typical lubricant coatings in the forward rod extrusion of stainless steels. For this purpose, the ferritic stainless steel X6Cr17 (DIN 1.4016) and the ferritic-austenitic stainless steel X2CrNiMoN22-5-3 (DIN 1.4462) are extruded with an equivalent plastic strain of ε̅ ≈ 1. The research is performed with a molybdenum disulfide (MoS2), a soap and a polymer-based lubricant coating. For reproducing different contact conditions, the die geometry is varied with die opening angles of 60°, 90° and 120°. The suitability of the lubricants is evaluated using the integrity of the lubricant coating after forming. From the correlations between process forces, temperatures and surface integrity, recommendations for the application of the researched lubricants are derived.

scholarly journals Elevated-Temperature Mechanical Properties of an Advanced-Type 316 Stainless Steel1

2000 ◽  
Vol 123 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Charles R. Brinkman
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Elevated Temperature ◽  
National Laboratory ◽  
Low Carbon ◽  
Oak Ridge ◽  
Creep Fatigue ◽  
Nippon Steel Corporation ◽  
Term Creep ◽  
Product Forms

Type 316FR stainless steel is a candidate material for the Japanese demonstration fast breeder reactor plant to be built in Japan early in the next century. Like type 316L(N), it is a low-carbon grade of stainless steel with a more closely specified nitrogen content and chemistry optimized to enhance elevated-temperature performance. Early in 1994, under sponsorship of The Japan Atomic Power Company, work was initiated at Oak Ridge National Laboratory (ORNL) aimed at obtaining an elevated-temperature mechanical-properties database on a single heat of this material. The product form was 50-mm plate manufactured by the Nippon Steel Corporation. Data include results from long-term creep-rupture tests conducted at temperatures of 500 to 600°C with test times up to nearly 40.000 h, continuous-cycle strain-controlled fatigue test results over the same temperature range, limited creep-fatigue data at 550 and 600°C, and tensile test properties from room temperature to 650°C. The ORNL data were compared with data obtained from several different heats and product forms of this material obtained at Japanese laboratories. The data were also compared with results from predictive equations developed for this material and with data available for types 316 and 316L(N) stainless steel.

The Effect of Nitrogen Alloying on the Low Cycle Fatigue and Creep-Fatigue Interaction Behavior of 316LN Stainless Steel

2013 ◽  
Vol 794 ◽  
pp. 441-448 ◽  
Author(s):  
G.V. Prasad Reddy ◽  
R. Sandhya ◽  
M.D. Mathew ◽  
S. Sankaran
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hold Time ◽  
Cyclic Plasticity ◽  
Dynamic Strain ◽  
Cycle Fatigue ◽  
Intergranular Cracking ◽  
Creep Fatigue

Low cycle fatigue (LCF) and Creep-fatigue interaction (CFI) behavior of 316LN austenitic stainless steel alloyed with 0.07, 0.11, 0.14, .22 wt.% nitrogen is briefly discussed in this paper. The strain-life fatigue behavior of these steels is found to be dictated by not only cyclic plasticity but also by dynamic strain aging (DSA) and secondary cyclic hardening (SCH). The influence of the above phenomenon on cyclic stress response and fatigue life is evaluated in the present study. The above mentioned steels exhibited both single-and dual-slope strain-life fatigue behavior depending on the test temperatures. Concomitant dislocation substructural evolution has revealed transition in substructures from planar to cell structures justifying the change in slope. The beneficial effect of nitrogen on LCF life is observed to be maximum for 316LN with nitrogen in the range 0.11 - 0.14 wt.%, for the tests conducted over a range of temperatures (773-873 K) and at ±0.4 and 0.6 % strain amplitudes at a strain rate of 3*10-3 s-1. A decrease in the applied strain rate from 3*10-3 s-1 to 3*10-5 s-1 or increase in the test temperature from 773 to 873 K led to a peak in the LCF life at a nitrogen content of 0.07 wt.%. Similar results are obtained in CFI tests conducted with tensile hold periods of 13 and 30 minutes. Fractography studies of low strain rate and hold time tested specimens revealed extensive intergranular cracking.

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