Heat treating

{
  "id": "MLC-T-ENV-013078",
  "term": "Heat treating",
  "field": "Environment",
  "term_source": "Heat Treating",
  "definition": "Modifying the physical properties of a part by applying controlled heating and cooling cycles. This operation includes tempering, carburizing, cyaniding, nitriding, annealing, aging, normalizing, austenitizing, austempering, siliconizing, martempering, and malleablizing. Parts are heated in furnaces or molten salt baths, and then may be cooled by quenching in aqueous solutions (e.g., brine solutions), neat oils (pure oils with little or no impurities), or oil/water emulsions. Heat treating typically is a dry operation, but is considered a wet operation if aqueous quenching solutions are used. Wastewater includes spent quench water and rinse water.",
  "subject": "Commercial processes",
  "references": [
    "40 CFR 438 Appendix B (CFR 2013)"
  ],
  "url": "https://mlchart.com/terminology/environment/heat-treating/"
}