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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=PHNlYXJjaD48cGFyYW1zPjxwYXJhbSBuYW1lPSJkYXRlaW4iIHZhbHVlPSJhbGwiIC8+PHBhcmFtIG5hbWU9InN1YmplY3Rsb2dpYyIgdmFsdWU9Im9yIiAvPjxwYXJhbSBuYW1lPSJ0ZXJtc2xvZ2ljIiB2YWx1ZT0ib3IiIC8+PHBhcmFtIG5hbWU9ImxvY2F0aW9uIiB2YWx1ZT0iMCIgLz48L3BhcmFtcz48ZmlsdGVycz48ZmlsdGVyIGZpZWxkPSJpbmRleHRlcm1zIiB2YWx1ZT0iJnF1b3Q7VGhlcm1pdCB3ZWxkaW5nJnF1b3Q7IiBvcmlnaW5hbF92YWx1ZT0iJnF1b3Q7VGhlcm1pdCB3ZWxkaW5nJnF1b3Q7IiAvPjwvZmlsdGVycz48cmFuZ2VzIC8+PHNvcnRzPjxzb3J0IGZpZWxkPSJwdWJsaXNoZWQiIG9yZGVyPSJkZXNjIiAvPjwvc29ydHM+PHBlcnNpc3RzPjxwZXJzaXN0IG5hbWU9InJhbmdldHlwZSIgdmFsdWU9InB1Ymxpc2hlZGRhdGUiIC8+PC9wZXJzaXN0cz48L3NlYXJjaD4=" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Fatigue life assessment of thermite welded rails based on laboratory tests and field measurement data</title>
      <link>https://trid.trb.org/View/2481398</link>
      <description><![CDATA[This in-depth study assesses the fatigue life of thermite-welded 60E1 rails by combining fatigue experimental tests with field measurement data. Material characterization, conducted using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), and Scanning Electron Microscopy (SEM), aimed to understand the fatigue behavior of these materials. The research was particularly focused on high-speed rail lines in South Korea, targeting areas with influence of track condition to collect strain data. By combining dynamic modulus calculations from high-speed tensile tests with the rain flow counting method for determining wheel loads, and employing the Linear Cumulative Damage method for estimating rail fatigue life, this study provides novel insights into the maintenance and durability of thermite welded rails. The integration of detailed laboratory experiments with field stress data offers a significant contribution to the predictive maintenance and lifecycle management of high-speed railway infrastructure.]]></description>
      <pubDate>Thu, 02 Jan 2025 10:14:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2481398</guid>
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    <item>
      <title>Investigation of Cause and Prevention Measures against Surface Defects on Thermit Welds</title>
      <link>https://trid.trb.org/View/1410936</link>
      <description><![CDATA[In Japan, four welding processes have been generally adopted for producing continuous welded rail (CWR): flash welding (FW), gas pressure welding (GPW), enclosed arc welding (EAW), and thermit welding (TW). Thermit welding method is the most popular rail welding process in Japan. The reliability of the thermit welds is high, because the failure rate has only been about 0.004 % over the last 10 years in Japan. However, recently there have been many cases where thermit welds are judged to be defective due to surface defects. Surface defects are often observed when welding new and worn rails. Welding test results show that surface defects are caused by gas generated from the contact of luting sand with molten steel which enters gaps between the welding mold and rail surface.]]></description>
      <pubDate>Mon, 20 Jun 2016 10:27:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1410936</guid>
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    <item>
      <title>Laser Cladding of Welds to Improve Railroad Track Safety</title>
      <link>https://trid.trb.org/View/1368241</link>
      <description><![CDATA[This project explores the use of a laser-based technology, laser cladding, to reduce surface and near-surface defects resulting from thermite field welds of rail. Thermite field welds are used to splice together continuous welded rail segments or to replace damaged sections of rail.  Thermite welds, however, often experience plastic deformation, or batter, along the heat affected zone (HAZ) of the weld. The objective of this project was to develop a procedure to prevent excessive plastic deformation along the HAZ by means of laser cladding coatings.  Initial project tasks included the evaluation of powders and the selection of a powder composition for use in the cladding process, and an investigation of alternative heat treatment protocols to solve a common cracking problem associated with laser cladding.  Sample sections of laser-cladded rail welds were then prepared using the revised process.  These test sections were installed and tested in the tracks at a testing facility.  The objective of these tests was to subject the test welds to 50 MGT (million gross tons) of heavy axle load train traffic and to monitor the performance of the cladded welds during the tests.  A preliminary assessment of the process necessary to apply laser cladding in the field was also conducted.  This included in situ heat treatment using induction heating and a preliminary assessment of other elements of the process including the use of computer numerical control  or robot arms.  Based on a limited sample of six welds made using the laser cladding procedure developed in this project the new heat treatment protocol appears to have solved the cracking problem.  The appearance of pores on two of test welds indicates the need for further investigation to determine the cause and cure for this problem. The delamination of the cladding on two welds installed in the test track also indicates the need for additional investigation.  Further consideration of laser cladding would also require a more comprehensive investigation of the entire process of laser cladding of thermite welds in the field from the standpoints of practicality and costs.]]></description>
      <pubDate>Wed, 09 Sep 2015 10:57:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/1368241</guid>
    </item>
    <item>
      <title>Standards struggle to keep up with the welders</title>
      <link>https://trid.trb.org/View/1340070</link>
      <description><![CDATA[Changes in track technology and the natural evolution of thermite welding techniques make it impossible for attempts to standardize welding processes in Europe to keep up. This poses problems for rail producers and welders, and this article outlines the challenges they face. Continuously welded rail, provided by aluminothermic welding, is a well-established process whose underlying technology has undergone constant improvements, resulting in a wide range of processes that exist for various rail types, profiles and grades. It is a reliable and highly dependable technology, but it can only continue to be successful with a combined understanding on the part of both rail producers and providers of welding technology.]]></description>
      <pubDate>Tue, 27 Jan 2015 11:23:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1340070</guid>
    </item>
    <item>
      <title>Testing New Weld Products at the Facility for Accelerated Service Testing</title>
      <link>https://trid.trb.org/View/1253474</link>
      <description><![CDATA[Transportation Technology Center, Inc., which regularly tests new or improved rail welding projects that are submitted by industry vendors, has recently tested two new weld products: the head alloyed weld and the head defect repair (HDR). The head alloyed weld was developed to provide increased weld running surface hardness in high-strength rails while the HDR developed an electric flash railhead repair weld that enables repair of defects while preserving the stress-free temperature of the rail. The head alloyed weld is a thermite weld that better matches the surface hardness of high-strength while maintaining the strength of a standard weld in the base. The HDR weld allows repair of railhead defects without cutting the full cross section of the rail, thus preserving the stress-free temperature of the rail. The head alloy thermite welds showed improved resistance to wear compared to standard unalloyed thermite welds while the HDR welds tended to be more sensitive to stress concentrators under the railhead.]]></description>
      <pubDate>Tue, 25 Jun 2013 08:57:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1253474</guid>
    </item>
    <item>
      <title>The effect of geometric features on multi-axial fatigue behaviour of aluminothermic rail welds</title>
      <link>https://trid.trb.org/View/1144238</link>
      <description><![CDATA[Aluminothermic rail welds typically exhibit a variable and often inferior performance when compared with flash butt welds. Fatigue failure as a result of surface defects or harsh geometric features in the presence of high axle loads and tractive forces gives rise to the so-called straight break and horizontal split web fractures. In this study, the reduction of fatigue performance due to geometric irregularities is investigated using a multi-axial high cycle fatigue criterion based on the critical plane concept. A thermo-structural finite element model of a track containing an aluminothermic weld is linked with a developed computer code to perform fatigue crack initiation analysis. Two geometrically different aluminothermic welds, one of which is widely used in Australian heavy haul railways, are investigated in terms of fatigue probability, to facilitate a better insight into the effect of weld collar shape and geometry at the edge of the weld collar on fatigue behaviour. The results confirm that the amount of fatigue damage is critically dependent on the geometric features of the collar edge, especially at the underhead radius which undergoes severe fatigue loading under some operational conditions.]]></description>
      <pubDate>Thu, 27 Sep 2012 11:06:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1144238</guid>
    </item>
    <item>
      <title>A simple approach to rail head repairs</title>
      <link>https://trid.trb.org/View/1114648</link>
      <description><![CDATA[Rail defects manifest themselves in various ways and various stages during the life of a rail, and they can be isolated or can affect a long rail length; isolated defects can be tackled in isolation. Aluminothermic welding offers a way to repair isolated rail surface flat defects, while avoiding the need to insert short plug sections and maintaining the integrity of the rail. The Thermit Head Repair (THR) process is a build up welding method based on the Thermit technology used for joining rails, and although the technology was originally developed about 50 years ago, it is time to revisit the technique, which this article does.]]></description>
      <pubDate>Wed, 14 Sep 2011 11:13:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1114648</guid>
    </item>
    <item>
      <title>Analysis of Thermite Welds in High-Carbon Rail Steels</title>
      <link>https://trid.trb.org/View/1099032</link>
      <description><![CDATA[This article describes an investigation conducted in order to better understand how the higher rail carbon content of premium rail steel affects thermite welding of rails. The findings are enabling the research of controlled cooling processes that can improve the overall weld performance in the heavy-axle-load environment. Sections are devoted to: understanding the rail/weld system, research into the effects of high carbon, heat-affected-zone effects, parent rail and weld, and a discussion of findings.]]></description>
      <pubDate>Mon, 18 Apr 2011 12:24:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/1099032</guid>
    </item>
    <item>
      <title>Development and Evaluation of Improved Rail Welding and Weld Treatment Methods</title>
      <link>https://trid.trb.org/View/887525</link>
      <description><![CDATA[This article focuses on improved rail welding technologies that are designed to extend service life. Three specific areas of rail welding technologies are discussed. The first involves the assessment of weld treatments intended to improve existing thermite weld performance using low frequency and high frequency vibration-based treatments. The article next evaluates new and improved rail welding technologies offered by different rail weld vendors. Focus is on thermite railhead repair welds. The article concludes with a discussion on the development of alternative rail welding processes that can serve as complements to existing field weld processes. Electroslag welding (ESW) is described as being a process that features cast microstructures similar to thermite welds. However, ESW welds exhibit fewer porosity or inclusion defects common to castings.]]></description>
      <pubDate>Thu, 30 Apr 2009 08:28:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/887525</guid>
    </item>
    <item>
      <title>Weld Defect Formation in Rail Thermite Welds</title>
      <link>https://trid.trb.org/View/805661</link>
      <description><![CDATA[In this article, a previously developed heat transfer model is used to study how welding parameters influence weld defect development in thermite welds. The authors use weld defect formation maps that are constructed from a series of heat transfer simulations. The authors find that for the current normal rail thermite welding conditions, shrinkage cavity formation can be avoided, though cold-lap and centre-line defects are likely to occur. The study also finds that by increasing the preheating time or the liquid temperature, the development of cold-lap and centre-line defects can be suppressed. However this can also lead to a slightly higher microporosity content in the railhead. As an alternative to increasing the preheating time or the liquid temperature, the authors find that the same effect can be achieved by increasing the 25 mm weld gap (standard) to a slightly larger value.]]></description>
      <pubDate>Wed, 25 Apr 2007 13:45:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/805661</guid>
    </item>
    <item>
      <title>Heat Transfer Modeling of Rail Thermite Welding</title>
      <link>https://trid.trb.org/View/798718</link>
      <description><![CDATA[Rail thermite welding is a valuable welding technology for the railroad industry due to its simplicity, portability, and economy. This paper describes a heat transfer analysis conducted by use of the finite element method. Only the heat transfer by conduction was simulated explicitly in the model, with the other thermally significant phenomena being included through the boundary and initial conditions. Despite these simplifications, the model can be used to analyze the thermal conditions during thermite welding with good accuracy. The predicted temperature history, weld deposit, and HAZ profiles were also in good agreement with the experimental measurements in laboratory welds. It was found that the weld gap is the most influential welding parameter for rail thermite welding. A wider gap weld appears to be less sensitive to chance variations in other welding parameters, and therefore fairly consistent thermal conditions can be obtained.]]></description>
      <pubDate>Thu, 01 Mar 2007 08:37:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/798718</guid>
    </item>
    <item>
      <title>The Shape of Things to Come: Welding and Grinding R&amp;D Remains a Priority Today so Railroads Have Better Options to Keep Rail in Top Form Tomorrow</title>
      <link>https://trid.trb.org/View/783461</link>
      <description><![CDATA[This article focuses on the welding and grinding needs of railroads in order to keep rails in good shape. Railroad maintenance officials look for grinding and welding processes that are easier to complete, require less track time, last a long time, but cost less.  Unfortunately, no thermite welds meet all four criteria. The author describes various products in research and development that may help meet these needs, including a robotic gas metal arc slot weld, high performance welds, and a new generation air/propane pre-heating system which can be used by only one operator.]]></description>
      <pubDate>Fri, 21 Jul 2006 14:34:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/783461</guid>
    </item>
    <item>
      <title>RAIL WELDING MARKET HEATING UP</title>
      <link>https://trid.trb.org/View/762088</link>
      <description><![CDATA[This article describes a number of new rail-welding products and innovations, and also discusses the nuances of their application. For example, a new slot weld vehicle can replace flawed railhead as quickly as 30 minutes and provides a higher quality gas-metal arc for better wear characteristics. Another innovation described is a computerized system for flash butt welders that analyzes the stages of pre-heating, flashing, boosting, upsetting, forging, and cooling and verifies the quality of the weld in accordance with its findings. A third product described is a three-piece multi-use rail modifier that minimizes flashing in the web and base areas. The article also discusses the successful market introduction of a DC-powered in-track welder.]]></description>
      <pubDate>Wed, 19 Oct 2005 12:45:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/762088</guid>
    </item>
    <item>
      <title>FIELD WELDING OF RAILS</title>
      <link>https://trid.trb.org/View/272673</link>
      <description><![CDATA[In the United States, thermite welding is most commonly used in the field for joining rails together.  Although thermite weldments possess relatively low ductility and impact toughness, when properly made their performance can be entirely satisfactory.  The search for alternative, higher integrity methods must recognize that only processes with approximately the same heat density as thermite (and electric flash butt) welding are likely to be easily applicable for rail welding.  Two such processes, a light weight, portable gas forge welding process and an enclosed electric arc process, appear to offer the prospects for practical application.  The character of the processes and the characteristics of typical weldments are reviewed.  The nature of the applied and residual stress state imposed upon weldments is described, and calculations are made to illustrate the susceptibility of thermite weldments to casting defects.  Different approaches to ultrasonic inspection are examined, and a decision tree for thermite weld quality assurance is described.]]></description>
      <pubDate>Sat, 28 Aug 2004 03:54:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/272673</guid>
    </item>
    <item>
      <title>STRUCTURE AND PROPERTIES OF THERMITE WELDS IN PREMIUM RAILS. FINAL REPORT</title>
      <link>https://trid.trb.org/View/272645</link>
      <description><![CDATA[Thermite welds were used to join combinations of premium rails and AREA Controlled Cooled Carbon rails (i.e., standard rails).  The premium rails comprised head-hardened rails and CrMo, CrV and Cr alloy rails.  A major objective was to determine the feasibility of joining premium rails to each other and to standard rails with the thermite welding process.  The objective was met in that metallurgically sound welds were produced using either "standard" or "alloy" thermite charges.  Other objectives were to determine mechanical properties and metallurgical structures of the weld-metal and of the heat-affected zones.  The "alloy" weld-metal was stronger than "standard" weld metal but had less tensile ductility.  Both types exhibit ductilities of only 2-6 percent reduction in area and impact energies of only 1.5-2.8 Joules at 20 deg C.  Tensile and impact specimens, which straddled the region of minimum hardness at the outer edge of the heat affected zone, show tensile ductilities of 19-60 percent reduction in area and only 2.6-6.9 Joules for impact energy.  In addition, temperature in the rail near the weld metal was measured as four of the welds were produced; in a fifth, temperatures in the weld metal, itself, were measured.  Finally, residual stresses were determined, and their effect on fatigue strength of welded rail is discussed.]]></description>
      <pubDate>Sat, 28 Aug 2004 03:53:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/272645</guid>
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