chemical reactions
... that some chemical reactions are used for welding rail tracks ?
... that some <b id="mwDY8"><a href="./Chemical_reaction" id="mwDZA" rel="mw:WikiLink" title="Chemical reaction">chemical reactions</a></b> are used for <a href="./Welding" id="mwDZE" rel="mw:WikiLink" title="Welding">welding</a> rail tracks <i id="mwDZI">(example pictured)</i>?