Test Methods to Assess Transverse Weld Metal Hydrogen Cracking

2008 ◽  
Vol 41-42 ◽  
pp. 427-434
Author(s):  
M. Law ◽  
D. Nolan
Keyword(s):  
Weld Metal ◽  
Steel Structures ◽  
Test Methods ◽  
Weld Bead ◽  
Test Method ◽  
Hydrogen Cracking ◽  
Weld Material ◽  
Point Bend ◽  
Haz Cracking ◽  
Transverse Weld

Hydrogen cracking in steel weldments can drastically reduce the toughness and ductility of welds in steel structures. Unfortunately, the development of the hydrogen economy will also see materials being increasingly exposed to hydrogen, in processes such as during hydrogen production and transportation. Thus, test methods are required which allow for a reproducible assessment of hydrogen embrittlement in weld material. In this article, rectangular test specimens made from weld bead on plate samples were subject to 4-point bend testing to investigate the relationship between applied stress, hydrogen content and embrittlement. This test concentrates the stresses in the weld bead, thus reducing the effects of premature HAZ cracking and enabling failure to develop in the weld metal, and showed good reproducibility. This test may form the basis for an industry test. Another test method is described using an un-machined weld bead on plate. A method of calculating the stresses and strains in this specimen in 4-point bending was developed.

Evaluation of Hydrogen Cracking in Weld Metal Deposited Using Cellulosic SMAW Electrodes

2006 ◽  
Author(s):  
Susan R. Fiore ◽  
Matthew A. Boring
Keyword(s):  
Weld Metal ◽  
Weather Conditions ◽  
Test Method ◽  
Manganese Concentration ◽  
Second Phase ◽  
Arc Length ◽  
Hydrogen Cracking ◽  
Power Sources ◽  
Multipass Weld ◽  
Coated Electrodes

In a previous study of the limitations of cellulosic coated electrodes, it was found that arc length has a pronounced effect on carbon, manganese, and silicon recovery in welds made using these electrodes. The effect of arc length could not explain the extremely rich compositions observed in a series of cracked girth welds that were analyzed, however. Subsequent investigation demonstrated that it was possible to effectively double the manganese concentration and triple the silicon concentration when using cellulosic-coated electrodes with low moisture contents in the coatings. A variety of multipass weld metal cracking tests were reviewed and a test method that can be performed as part of a procedure qualification/material qualification test to determine appropriate preheat/interpass temperatures was developed. This paper describes the results of a follow-on program funded by Pipeline Research Council International (PRCI) and the US Department of Transportation. The objectives of the program were to further define the conditions that can lead to hydrogen cracking in weld metal deposited using cellulosic coated electrodes, in terms of operator preference (arc length), electrode properties, power supply selection, and materials handling, and to develop welding and safe handling guidelines to prevent weld metal hydrogen cracking. Cellulosic coated electrodes were procured from several manufacturers. Initially, they were checked for weld metal chemical composition in the as-received and dried conditions. The coating moisture of each electrode in each condition was also determined. Some of the electrodes were selected for additional testing in the as-received, dried and re-hydrated conditions. Pipe sections were welded with each electrode in each condition, using both a short arc length and a medium arc length. Weld metal testing included tensile testing, bend testing and weld metal chemical analysis. In the second phase of this program, additional welds were made with two of the electrodes using different power sources. Electrodes were also exposed to conditions intended to simulate actual weather conditions from around the world, in an effort to produce guidelines for maximum exposure times at the various conditions.

Crack Tip Opening Displacement of X100 SAWL Pipe

2011 ◽  
Vol 299-300 ◽  
pp. 292-297
Author(s):  
Qing Ren Xiong ◽  
Jun Liu ◽  
Jian Xun Zhang ◽  
Yao Rong Feng ◽  
Wen Zhen Zhao
Keyword(s):  
Fracture Toughness ◽  
Base Metal ◽  
Weld Bead ◽  
Test Method ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Crack Propagation Resistance ◽  
Temperature Fracture ◽  
Three Point Bend Test ◽  
Point Bend

The fracture toughness of different zones of X100 SAWL pipe was studied by three-point bend test method under different temperature. At the same temperature, the crack propagation resistance and tear modulus of X100 SAWL pipe distributed as: base metal>HAZ>weld bead, and the distribution of the CTOD value of X100 SAWL pipe is :base metal >weld bead >HAZ. Further investigation was conducted to analyze the decrease of fracture toughness (especially low temperature fracture toughness) and the occurrence of local unstable phenomenon in HAZ specimens.

An evaluation of ECT sample height for small flute board grades and Box Manufacturer’s Certification compliance

TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 24-28
Author(s):  
CORY JAY WILSON ◽  
BENJAMIN FRANK
Keyword(s):  
Compressive Strength ◽  
Compressive Load ◽  
Test Sample ◽  
Test Methods ◽  
Test Method ◽  
Initial Development ◽  
Sample Height ◽  
Relationship Of ◽  
The Relationship ◽  
Corrugated Fiberboard

TAPPI test T811 is the specified method to ascertain ECT relative to box manufacturer’s certification compliance of corrugated fiberboard under Rule 41/ Alternate Item 222. T811 test sample heights were derived from typical board constructions at the time of the test method’s initial development. New, smaller flute sizes have since been developed, and the use of lighter weight boards has become more common. The T811 test method includes sample specifications for typical A-flute, B-flute, and C-flute singlewall (and doublewall and triplewall) structures, but not for newer thinner E-flute or F-flute structures. This research explores the relationship of ECT sample height to measured compressive load, in an effort to determine valid E-flute and F-flute ECT sample heights for use with the T811 method. Through this process, it identifies challenges present in our use of current ECT test methods as a measure of intrinsic compressive strength for smaller flute structures. The data does not support the use of TAPPI T 811 for ECT measurement for E and F flute structures, and demonstrates inconsistencies with current height specifi-cations for some lightweight B flute.

scholarly journals Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Experimental Tests ◽  
Induction Machines ◽  
Test Methods ◽  
Operating Conditions ◽  
Test Method ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

scholarly journals Concept and Realization of a Novel Test Method Using a Dynamic Test Stand for Detecting Persons by Sensor Systems on Autonomous Agricultural Robotics

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2315
Author(s):  
Christian Meltebrink ◽  
Tom Ströer ◽  
Benjamin Wegmann ◽  
Cornelia Weltzien ◽  
Arno Ruckelshausen
Keyword(s):  
Environmental Conditions ◽  
Dynamic Test ◽  
Test Methods ◽  
Test Stand ◽  
Human Detection ◽  
Test Method ◽  
Sensor Systems ◽  
Functional Safety ◽  
Agricultural Robots ◽  
Agricultural Robotics

As an essential part for the development of autonomous agricultural robotics, the functional safety of autonomous agricultural machines is largely based on the functionality and robustness of non-contact sensor systems for human protection. This article presents a new step in the development of autonomous agricultural machine with a concept and the realization of a novel test method using a dynamic test stand on an agricultural farm in outdoor areas. With this test method, commercially available sensor systems are tested in a long-term test around the clock for 365 days a year and 24 h a day on a dynamic test stand in continuous outdoor use. A test over a longer period of time is needed to test as much as possible all occurring environmental conditions. This test is determined by the naturally occurring environmental conditions. This fact corresponds to the reality of unpredictable/determinable environmental conditions in the field and makes the test method and test stand so unique. The focus of the developed test methods is on creating own real environment detection areas (REDAs) for each sensor system, which can be used to compare and evaluate the autonomous human detection of the sensor systems for the functional safety of autonomous agricultural robots with a humanoid test target. Sensor manufacturers from industry and the automotive sector provide their sensor systems to have their sensors tested in cooperation with the TÜV.

Research the Test Method of the Voltage Transformer Secondary Load in the Three-Phase Three-Wire Electric Energy Metering Device

2014 ◽  
Vol 687-691 ◽  
pp. 3110-3115
Author(s):  
Gu Li ◽  
Zi Ming Fu ◽  
Jie Feng Yan ◽  
Bing Wen Li ◽  
Zhi Rong Cen
Keyword(s):  
Power Supply System ◽  
Electric Energy ◽  
Test Methods ◽  
Test Method ◽  
Testing Methods ◽  
Voltage Transformer ◽  
Secondary Load ◽  
Three Phase ◽  
Energy Metering ◽  
Definition Of

This paper analyzes and studies the definition of the voltage transformer secondary load, examines the practical purposes of the measured values of the voltage transformer secondary load, and presents a variety of testing methods to analyze and compare the differences. This paper gives the test methods of the voltage transformer secondary load when the connection of the voltage transformer is the Y / Y in a three-phase three-wire power supply system, filling the blank of this type of test method in the industry. When other units within the industry carry out such work, the conclusions of this paper are available for reference, and the conclusions of this paper can be referred when drafting relevant regulations in the future.

Analysis of the Test Method of Quartz Glass Optical Homogeneity

2017 ◽  
Vol 726 ◽  
pp. 414-418
Author(s):  
Bo Fu ◽  
Hui Wang ◽  
Zhu Feng Shao
Keyword(s):  
Quartz Glass ◽  
Measurement Accuracy ◽  
Test Methods ◽  
Test Method ◽  
Wavefront Aberration ◽  
Optical Homogeneity ◽  
Advantages And Disadvantages ◽  
Interference Measurement ◽  
Optical Quartz Glass

The optical quartz glass is widely applied in optical system , photo communications，inertial navigation，etc.It must have high optical homogeneity. Optical homogeneity of the optical quartz glass directly affects the wavefront quality of the optical transmission system, and changes the wavefront aberration of the system. How to accurately determine the optical homogeneity of the quartz glass is especially important. Currently，the method of test for optical homogeneity mainly used by interference principle. This paper analyzes various existing interference measurement method and test equipment. Summarized the advantages and disadvantages of various test methods，using range and measurement accuracy.

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