Matthias Bruchhausen

Small punch tensile/fracture test data and 3D specimen surface data on Grade 91 ferritic/martensitic steel from cryogenic to room temperature

Raw data from small punch tensile/fracture tests at two displacement rates in the temperature range from −196 °C to room temperature on Grade 91 ferritic/martensitic steel are presented. A number of specimens were analyzed after testing by means of X-ray computed tomography (CT). Based on the CT volume data detailed 3D surface maps of the specimens were established. All data are open access and available from Online Data Information Network (ODIN)https://odin.jrc.ec.europa.eu. The data presented in the current work has been analyzed in the research article “On the determination of the ductile to brittle transition temperature from small punch tests on Grade 91 ferritic-martensitic steel” (M. Bruchhausen, S. Holmström, J.-M. Lapetite, S. Ripplinger, 2015) [1].

Impact of High Pressure Hydrogen Atmosphere on the Mechanical Properties of Haynes 282 Superalloy

Abstract Haynes 282 alloy is a newly developed nickel-base superalloy, with properties focussed on high creep strength, thermal stability, good weldability and fabricability, which might qualify it as a substitute for established materials like Hastelloy-X or René-41 e.g. in aerospace applications. However, so far no information on the sensitivity for hydrogen environment embrittlement (HEE) has been published for this material. In the present work, tensile tests under hydrogen atmosphere have been carried out at room temperature and the results have been compared to those from tests under argon. Haynes 282 is found to show significant hydrogen embrittlement.

Small punch tensile/fracture test data for P92 nt material at -150 °C and a displacement rate of .00833 mm/s

Data collection containing small punch tensile/fracture data for tests on Grade 91 ferritic/martensitic steel performed between cryogenic and room temperatures. The material has the same chemical composition as P91/ T91 but is supplied in form of a plate rather than as pipe (P91) or tube (T91). The particular batch of Gr. 91 used in the present work (S50460) as part of the FP7 project MATTER was originally produced for the FP6 project EUROTRANS (project domain 4: DEMETRA). Disc-shaped small punch (SP) specimens as specified in the European Code of Practice were used. Their diameter was 8 mm and their thickness 0.5 mm. The surface roughness was less than Ra = 0.15 um on both sides. SP tensile/fracture mechanics tests were performed with varying displacement rates and temperatures as listed in Table 1. On the specimens tested at 0.5 mm/s X-ray computed tomography analysis has been carried out and the 3D surface has been reconstructed. URI: https://odin.jrc.ec.europa.eu [1] Authors: BRUCHHAUSEN Matthias LAPETITE Jean-Marc Publication Year: 2015 Science Areas:

Small punch tensile/fracture test data for P92 material at 23 °C and a displacement rate of .00833 mm/s

Small punch tensile and creep data obtained in a round robin exercise for the elaboration of an EN standard on small punch testing. For estimating the tensile properties a series of tests were carried out at room temperature on Gr. 91 steel with different heat treatments. Further tests were performed at varying temperatures between 77K and room temperature to determine the ductile to brittle transition temperature (DBTT). Creep tests were carried out at temperatures in the range 550-650 oC.

Impact of High-Pressure Gaseous Hydrogen on the Fatigue Behaviour of Austenitic Steel A-286 under Asymmetric Loading Conditions

Ultrasonic techniques are an established means for carrying out fatigue tests at very highnumbers of cycles. These techniques are based on the formation of a standing ultrasonic wave inthe specimen and usually use frequencies around 20 kHz. Although such systems allow testing to avery high number of cycles in a relatively short time, the use of a standing wave for creating thestrains restricts them to symmetric push-pull mode. This limitation can be overcome by coupling an ultrasonic test device to a universal test rig. In this work a different approach is presented that is particularly well suited for studying environmental effects. The load train with the specimen is enclosed in a pressure vessel. An acoustic horn divides this pressure vessel into two separate chambers. Applying a pressure difference between the two chambers then leads to a static stress in the specimenon which the oscillating stress from ultrasonic excitation is superposed. The addition of both stresses allows testing at varying R ratio. The deteriorating effect of high-pressure gaseous hydrogen on the steel A-286 is investigated as function of oscillating and static stresses at room temperature. SEM analysis of the fracture surface is presented.

Simulation of the High Cycle Fatigue Life Reduction due to Internal Hydrogen Embrittlement Using a Commercial Finite Element Program

The effect of internal hydrogen on the high cycle fatigue (HCF) life duration of Inconel X-750® in the hydrogen concentration range between 5 and 39 wppm at ambient temperature was investigated using an ultrasonic HCF test bench. For an alternating stress equal to 0.6 times the yield stress of the hydrogen-free material, a drop of two orders of magnitude in the high-cycle fatigue durability of the material has been measured over the investigated hydrogen concentration range. New tools have been developed to predict with little efforts the drop in life duration due to internal hydrogen embrittlement and the localization of the fracture area by Finite Element simulations. A simple approach has been considered to rapidly get a first assessment of the drop magnitude in HCF life duration of a structure due to internal hydrogen embrittlement at steady state hydrogen concentration conditions. The core of this proposed Finite Element calculation-based method is the “double Wohler curve”, i.e. a three-dimensional Wohler curve with the hydrogen concentration as the third dimension.