Influence of Tempering on Mechanical Properties of Induction Bents below 540°C

The article describes basic principles of induction bending and the change of mechanical properties from as received (straight) pipe made from HSLA steel to induction bend. The main purpose of this article is to experiment with tempering temperatures below 540°C. After tempering at 540°C which is the lowest recommended temperature for post bend heat treatment (PBHT) according to CSA specifications (Canadian Standards Association) the induction bend area in many cases does not achieve the minimum required mechanical properties and therefore it is not accepted for usage. In this article mechanical properties such as tensile, toughness, hardness are evaluated. Also the article contains microstructural analyses and comparison of bended and heat treated samples.