Promoted ignition-combustion is a term which has been used to describe a situation where a substance with poor oxygen compatibility ignites and supports the combustion of a more resistant material. Previous papers on the subject in recent years have reported on the investigation of this phenomenon as it related to carbon steel, stainless steels and a number of engineering alloys. However, the bulk of these investigations have involved relatively high pressures.
Carbon steel is a common alloy used in the construction of equipment used in industrial gas applications. Yet, promoted ignition-combustion test data on carbon steel samples showing the effects of variables such as test pressure, oxygen purity, temperatures, section size, promoter types, etc. on promoted ignition-combustion behavior are scarce; particularly, at low pressures.
In this investigation, the promoted-ignition combustion behavior of carbon steel was studied in oxygen-nitrogen gas mixtures over the pressure range of 0.118 MPa to 0.446 MPa with oxygen purities ranging from 70% to 99.7%. Comparative tests were made using 3.175 mm and 6.35 mm diameter rods at pressures up to 0.273 MPa. Over the pressure and purity ranges tested, there was little difference due to size effects. Carbon steel burns occurred at pressures as low as 0.118 MPa with oxygen purities of 95% and above, in the promoted ignition-combustion tests.