The Relation between Creep Rupture Time and Minimum Creep Rate of Austenitic Stainless Steel

1973 ◽  
Vol 22 (234) ◽  
pp. 298-303
Author(s):  
Tadashi KAWASAKI ◽  
Masakazu HORIGUCHI
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Creep Rate ◽  
Minimum Creep Rate ◽  
Creep Rupture ◽  
Rupture Time

On Time-Temperature Parameters for Correlation of Creep-Rupture Data in Stainless Steel Weldments

1978 ◽  
Vol 100 (3) ◽  
pp. 319-332 ◽  
Author(s):  
W. E. White ◽  
Iain Le May
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Creep Rate ◽  
Creep Rupture ◽  
Rupture Time ◽  
Function Approach ◽  
Secondary Creep ◽  
Rupture Data ◽  
The Relationship ◽  
Secondary Creep Rate

The Manson-Haferd, Larson-Miller, and Orr-Sherby-Dorn time-temperature parameters were applied to creep-rupture data obtained from testing two batches of austenitic stainless steel weldments. It was found that none of these correlated the data satisfactorily. A new parameter, based on a modification of one proposed originally by Manson and by Goldhoff and Sherby, was found to adequately correlate the data. The Minimum-Commitment, Station-Function Approach of Manson and Ensign was also applied, the results of which supported those obtained from the analysis made using the parameters listed above. Finally, from the relationship between rupture-time and secondary creep-rate, it is suggested that the form of the rupture data may be useful in predicting the physical basis for creep.

Very-Short-Time, Very-High-Temperature Creep Rupture of Type 347 Stainless Steel and Correlation of Data

1969 ◽  
Vol 91 (1) ◽  
pp. 32-38 ◽  
Author(s):  
C. D. Lundin ◽  
A. H. Aronson ◽  
L. A. Jackman ◽  
W. R. Clough
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Minimum Creep Rate ◽  
Creep Rupture ◽  
Aisi Type ◽  
Data Scatter ◽  
Long Time ◽  
Short Time ◽  
Very High ◽  
Rupture Behavior

Available equipment initially developed for welding research studies was used to investigate the creep-rupture behavior of AISI type 347 stainless steel in a very-high-temperature range from 62 to 86 percent of the solidus. Stress applications from 900 to 28,000 psi gave rupture times from a fraction of a second to several hundred seconds with thousandfold variations of minimum creep rate. Results could be presented by conventional means. Data scatter on a Monkman-Grant plot was typical. Correlation and extrapolation procedures developed by Larson-Miller, Manson-Haferd, Dorn, Korchynsky, and Conrad for conventional long-time results were found to be applicable, with preference being given to the Manson-Haferd procedures.

Creep Deformation Behavior and Microstructural Degradation During Creep of Pre-Strained 25Cr-20Ni-Nb-N Steel

2007 ◽  
Author(s):  
Nobuhiko Saito ◽  
Nobuyoshi Komai
Keyword(s):  
Creep Rate ◽  
Creep Deformation ◽  
Deformation Behavior ◽  
Minimum Creep Rate ◽  
Strengthening Mechanism ◽  
Creep Rupture ◽  
Microstructural Degradation ◽  
Solution Treated ◽  
Long Time ◽  
Strained Materials

The purpose of this study is to clarify the creep deformation behavior and microstructural degradation during creep of pre-strained 25Cr-20Ni-Nb-N steel (TP310HCbN), which has the highest creep strength among austenite stainless steels used for boiler tubes. The creep rupture strengths of the 20% pre-strained materials tested at 650°C under 210 MPa and 180 MPa were higher than those of solution-treated materials. However, the long time creep rupture strengths of the 20% pre-strained materials tested at 700°C and 750°C were lower than those of solution-treated materials. Thus, the creep strengths of the prestrained materials depend on test temperature and stress. Furthermore, the minimum creep rate of the 20% pre-strained materials and re-solution-treated materials tested at 650°C under 300MPa were 1.2 × 10−9 and 1.6 × 10−8 s−1, respectively. Thus, the minimum creep rate of the 20% pre-strained materials was lower than for re-solution-treated materials. The creep strengthening mechanism of the pre-strained materials at 650°C was considered to be that high-density dislocations were maintained until the late stage of creep. On the other hand, the creep rupture strengths of the 20% pre-strained materials were lower than those of solution-treated materials tested at over 700°C because of agglomeration and coarsening of precipitates and the recovery of dislocations.

Comparison of creep rupture behaviour of type 316L(N) austenitic stainless steel joints welded by TIG and activated TIG welding processes

2011 ◽  
Vol 528 (22-23) ◽  
pp. 6971-6980 ◽  
Author(s):  
T. Sakthivel ◽  
M. Vasudevan ◽  
K. Laha ◽  
P. Parameswaran ◽  
K.S. Chandravathi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Creep Rupture ◽  
Tig Welding ◽  
Type 316L ◽  
Steel Joints ◽  
Welding Processes

Creep property measurement of service-exposed SUS 316 austenitic stainless steel by the small-punch creep-testing technique

2002 ◽  
Vol 17 (8) ◽  
pp. 1945-1953 ◽  
Author(s):  
Maribel L. Saucedo-Muñoz ◽  
Shin-Ichi Komazaki ◽  
Toru Takahashi ◽  
Toshiyuki Hashida ◽  
Tetsuo Shoji
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Creep Test ◽  
Creep Resistance ◽  
Creep Property ◽  
Creep Rupture ◽  
Secondary Creep ◽  
Small Punch ◽  
Uniaxial Creep ◽  
Small Punch Creep Test

The creep properties for SUS 316 HTB austenitic stainless steel were evaluated by using the small-punch creep test at 650 °C for loads of 234, 286, 338, 408, and 478 N and at 700 °C for loads of 199 and 234 N. The creep curves, determined by means of the small-punch creep test, were similar to those obtained from a conventional uniaxial creep test. That is, they exhibited clearly the three creep stages. The width of secondary creep stage and rupture time tr decreased with the increase in testing load level. The creep rupture strength for the service-exposed material was lower than that of the as-received material at high testing loads. However, the creep resistance behavior was opposite at relatively low load levels. This difference in creep resistance was explained on the basis of the difference in the creep deformation and microstructural evolution during tests. It was also found that the ratio between the load of small-punch creep test and the stress of uniaxial creep test was about 1 for having the same value of creep rupture life.

On Statistical Properties of High Temperature Creep Rupture Data in STS304 Stainless Steels

2006 ◽  
Vol 326-328 ◽  
pp. 553-556
Author(s):  
Seon Jin Kim ◽  
Yu Sik Kong ◽  
Young Jin Roh ◽  
Won Taek Jung
Keyword(s):  
Steady State ◽  
Creep Rate ◽  
Stainless Steels ◽  
Probability Distributions ◽  
Creep Rupture ◽  
Steady State Creep ◽  
Rupture Time ◽  
Steady State Creep Rate ◽  
Rupture Data ◽  
Short Time

This paper deals with the statistical properties of short time creep rupture characteristic values (for example, creep rupture time, steady state creep rate, total creep rate, initial strain, etc.) in STS304 stainless steels. From short time creep rupture tests performed by constant stresses at three different elevated temperatures 600, 650 and 700, the scatter and probability distributions were investigated for rupture time, total creep rate, steady state creep rate, initial strain, and others. The effect of temperature on the statistical scatter of rupture time was the smallest at 700. The effect of stress on the statistical scatter of rupture time was smaller with increasing stresses. The probability distributions of short time creep rupture data were well followed 2-parameter Weibull.

On Creep Rupture Characteristics in STS304 Stainless Steels

2006 ◽  
Vol 326-328 ◽  
pp. 1309-1312
Author(s):  
Seon Jin Kim ◽  
Yu Sik Kong ◽  
Young Join Noh ◽  
Won Taek Jung ◽  
Sang Woo Kwon
Keyword(s):  
Steady State ◽  
Creep Rate ◽  
Stress Exponent ◽  
Stainless Steels ◽  
Elevated Temperatures ◽  
Creep Rupture ◽  
Steady State Creep ◽  
Rupture Time ◽  
Steady State Creep Rate ◽  
Creep Stress

In this study, the creep rupture tests of STS304 stainless steels were investigated at three different elevated temperatures of 600, 650 and 700 under the constant creep stresses. Creep rupture characteristics such as creep stress, creep rupture time, steady state creep rate and so on were evaluated. The behaviors of creep rate curve and initial strain are compared at three different elevated temperatures. The stress exponent (n) at 600, 650 and 700 based on steady state creep rate showed 22.5, 20.6 and 11.4 respectively. By increasing the temperature, the stress exponent is decreased. At the temperature of 700, the lowest stress exponents are shown and this behavior is also observed in the case of stress exponent based on rupture time. The creep life prediction by LMP method is presented and the equation of this result is as follows: T(logtr+20)=-0.005152-14.56+24126.

Time to Initiation of Tertiary Creep Property of Grade 91 Steels

2016 ◽  
Author(s):  
Kazuhiro Kimura ◽  
Kota Sawada
Keyword(s):  
Creep Rate ◽  
Minimum Creep Rate ◽  
Rupture Life ◽  
Creep Rupture ◽  
Tertiary Creep ◽  
Time To Initiation ◽  
Wide Range ◽  
Minimum Stress ◽  
Grade 91

Creep deformation property of Grade 91 steels was analyzed on more than 370 creep curves over a wide range of time to rupture from about 10 hours to beyond 100,000 hours, in order to evaluate time to 1% total strain, time to minimum creep rate and time to initiation of tertiary creep. Time to initiation of tertiary creep was assessed as a 0.2% offset with a slope of minimum creep rate. It is difficult to determine time to minimum creep rate precisely, which is a basis of 0.2% offset, however, it has been confirmed that time to initiation of tertiary creep is not sensitive to the time when the creep rate indicates minimum value. Life ratio of 1% total strain time against creep rupture time increases up to about 60% with increase of temperature and decrease of stress. Life ratio of time to initiation of tertiary creep also tends to increase with decrease in stress. However, change of it is in a range of 50 to 60% of creep rupture life over a wide range of creep rupture life from 10 hours to 100,000 hours, and it is not sensitive to creep test temperature. Over a range of temperatures from 500 to 600°C and up to about 200,000 hours, a temperature and time-dependent stress intensity limit, St is controlled by 67% of minimum stress to rupture. However, a difference between 67% of minimum stress to rupture and 80% of minimum stress to initiation of tertiary creep decreases with increases in temperature and time, and both values approach each other in the long-term beyond about 100,000 hours at 600°C. In the long-term beyond about 10,000 hours at 650°C, St is controlled by 80% of minimum stress to initiation of tertiary. The stable life fraction of time to initiation of tertiary creep establish a reliability of a temperature and time-dependent stress intensity limit value.

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