heating vs welding

heating

noun
  • A system that raises the temperature of a room or building. Compare heater. 

  • The act of making something hot. 

adj
  • Causing heat. 

welding

noun
  • joining two materials (especially two metals) together by applying heat, pressure and filler, either separately or in any combination, or 

  • binding together inseparably; uniting closely or intimately. 

How often have the words heating and welding occurred in a corpus of books? (source: Google Ngram Viewer )