Download or read book A Model for Predicting Fracture Toughness of Steels in the Transition Region from Hardness written by M. Wagenhofer and published by . This book was released on 2003 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given the nature of fracture in the lower transition region where final fracture by cleavage is preceded by some amount of plastic deformation, it is appropriate to use a combined strength-strain criterion to describe the conditions at fracture. A dislocation- based model for predicting fracture toughness of steels in the transition region has been developed where the primary feature describing the temperature dependence of fracture toughness is a plastic work term of the following form: ?eff=(?m? ̄)f??ZAd?p ̄.D0 where ?eff is the effective plastic work to fracture, d?p is the effective plastic strain increment, ?m/ ̄? is the triaxiality ratio and r0 is the length scale of the critical fracture event typically taken as carbide cracking*(and thus D0 = r0 is the critical carbide radius). The ?ZA term represents the flow stress from the Zerilli-Armstrong constitutive equation for bcc metals. This term introduces a temperature dependency based on dislocation mechanics considerations. Inserting the first equation into the Griffith-Orowan equation for fracture stress leads to the elimination of the carbide radius from the equation, ?f=[?E?eff2(1-?2)r0]1/2 and thus the need for defining a characteristic distance.

Download or read book Fracture Toughness Testing and Its Applications written by and published by ASTM International. This book was released on 1965 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Properties Related to Fracture Toughness written by and published by ASTM International. This book was released on 1976 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Properties Related to Fracture Toughness written by Volker Weiss and published by ASTM International. This book was released on 1976 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fracture Toughness of High strength Materials Theory and Practice written by and published by . This book was released on 1970 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transition Toughness Modeling of Steels Since RKR written by M. Wagenhofer and published by . This book was released on 2004 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we trace the development of transition fracture toughness models from the landmark paper of Ritchie, Knott, and Rice in 1973 up through the current day. While such models have become considerably more sophisticated since 1973, none have achieved the goal of blindly predicting fracture toughness data. In this paper we suggest one possible way to obtain such a predictive model.

Download or read book A Physics Based Predictive Model for Fracture Toughness Behavior written by M. Wagenhofer and published by . This book was released on 2004 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using the Zerilli-Armstrong (ZA) constitutive model for BCC materials and a combined strength-strain model of fracture, a physics model suitable for predicting the fracture toughness transition behavior of ferritic steels has been developed. The model predicts an exponential dependence of the plastic work on temperature and thus is comparable to the exponential dependence of plastic work predicted by Wallin et al. for the Master Curve. Exploring the limits of applicability of the ZA equation used as the basis for this model provides the information required to firmly establish the limits of material condition applicability of the Master Curve. Calculations based on limited data provide validation of the proposed model. The models ability to predict shifts in transition temperature with irradiation and its application to RP vessel integrity assessment will also be discussed.

Download or read book Fracture Toughness Testing and Its Applications written by and published by . This book was released on 1965 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applications of Fracture Toughness Parameters to Structural Metals written by Metallurgical Society of AIME. and published by . This book was released on 1966 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fracture Toughness Predictions for Modern Low carbon High strength Steels Based on Microstructural and Micromechanistic Approaches written by and published by . This book was released on 2002 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Statistical Characterization of Fracture in the Transition Region written by JD. Landes and published by . This book was released on 1980 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fracture toughness results are measured in the transition region for an ASTM A471 Ni-Cr-Mo-V steel on two specimen sizes 1T compact tension (CT) and 4T-CT. The results are typical for steels in the transition in that the smaller specimen toughness values are greater than the larger specimen results. Two explanations are given for this behavior. One explanation, based on loss of constraint, suggests that small specimens cannot be used to characterize the toughness of a large structure in the transition region. A second explanation, based on a statistical model, suggests that small specimen results when properly analyzed can be used to characterize the toughness of large structures.

Download or read book Steel Transition Fracture Toughness Reference Temperature Determination written by and published by . This book was released on 1998 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Quantitative measurements of cracking resistance are needed to assess the risk of brittle fracture under service conditions in warships. This requires laboratory toughness testing at the minimum service temperature and at loading rates equivalent to hull impact events such as wave slamming and minor collisions. A technique has recently been standardized for determining the fracture toughness of ferritic marine construction steels and welds in the brittle-ductile transition range. In this technique, toughness transition curves are generated statistically from the analysis of toughness data populations using a master curve concept. This report describes a preliminary series of tests to evaluate 350WT steel plate using this approach and to establish the degree to which such a procedure will provide useful data for structural integrity analyses.

Download or read book Prediction of Variation in Fracture Toughness K Sub Ic from Small Specimen Tests written by Alan S. Tetelman and published by . This book was released on 1970 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Charpy transition temperature and low temperature fracture toughness of low alloy steels depend on three parameters; the microcleavage strength, the yield strength, and the critical crack tip radius. Microcleavage strength and critical crack tip radius appear to be essentially independent of temperature in low alloy steels. A method was developed for relating the change in transition temperature to the change in Charpy transition temperature, since both of these macroscopic measures of toughness depend on the same microscopic parameters. The method for making these calculations and predictions is described. (Author).

Download or read book Predicting the Temperature and Strain Rate Dependences of the Cleavage Fracture Toughness of Ferritic Steels written by D. A. Curry and published by . This book was released on 1979 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Closer Look at Effects of the Loading Rate on Fracture Toughness in the Ductile to Brittle Transition Regime of a Ferritic Steel written by Hans-Jakob Schindler and published by . This book was released on 2015 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: An increased loading rate causes not only a shift of the ductile-to-brittle transition curve, but also a slight change of the shape of this curve. The latter tends to become steeper as the loading rate increases. This effect was observed even at loading rates that are considered to be quasi-static according to ASTM E1921-13: Standard Test Method for Determination of Reference Temperature, T0, for Ferritic Steels in the Transition Range, Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2013. Actually, the coefficient 0.019 in the exponent of the MC turned out to be substantially higher at elevated loading rates. This means that a basic assumption of the evaluation procedure of ASTM E1921 is not met, which leads to an increased uncertainty of T0 or T0,x, respectively. This effect of is most pronounced in testing at elevated loading rates using the single-temperature option. An improved method to determine the reference temperature is proposed, where the exponent in the median transition curve in ASTM E1921 is considered to be an open parameter. The resulting reference temperatures, denoted as T100 andT100,x, respectively, are expected to be more accurate than standard T0, which is confirmed by comparison with experimental data. Furthermore, the validity requirements for T100 are less restrictive and more suitable than those in ASTM E1921, since they do not depend on the outcome of the tests. Based on the improved data, an improved estimation formula for the rate-induced shift of T0 is derived. Suggestions are made for improvement of ASTM E1921.

Download or read book Prediction of Fracture Toughness of 10MnNi2Mo Steel written by B. Strnadel and published by . This book was released on 1988 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fracture Toughness of Ferritic Steels in the Ductile to Brittle Transition Region written by Carlos Berejnoi and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ferritic steels, as other materials, have different failure modes depending on the temperature. At elevated temperatures, they behave as ductile materials, while at low temperatures they are brittle. There is an intermediate temperature region where these alloys have a failure mode resulting from the competition between cleavage and ductile mechanisms. This region is known as the ductile-to-brittle transition zone. The characterization of fracture resistance of ferritic steels in the ductile-to-brittle transition region is problematic due to scatter in results, as well as size and temperature dependences. American Society for Testing and Materials (ASTM) has standardized the determination of a temperature reference (T0) for the fracture toughness characterization of ferritic steels in this region. This chapter presents the evolution of the statistical treatment of fracture toughness data until the present, including some comments on T0 determination, and some aspects that require a deeper analysis.