Hardness testing as a method to identify the highest-temperature combustion zone in transport fires

¹ Saint - Petersburg University of the State Fire Service of of EMERCOM of Russia, 196105 Saint Petersburg, Russia
² Higher School of Technosphere Safety of Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
³ Saint - Petersburg Mining University, 199106 Saint Petersburg, Russia
⁴ Mining Institute of the Ural Branch of the Russian Academy of Science, 614007 Perm, Russia
⁵ Saint-Petersburg State University of Industrial Technologies and Design, 191186 Saint Petersburg, Russia

^* Corresponding author: sikorova.g@igps.ru

Abstract

This article presents some results on the selection of the necessary micro-hardness tester for the purposes of research. In accordance with the objectives, namely the scientifically based choice of a hardness meter for the purposes of fire-technical examination and evaluation of its capabilities, aimed primarily at the possibility of identifying the most high-temperature combustion zone in fires in transport. The selection of a device for measuring microhardness was carried out in accordance with current methods for measuring microhardness, first of all for determination of microhardness for products based on metals and their alloys, as well as materials found in vehicles. The paper describes the main types of hardness testers and their applications. On the basis of the analysis programmable electronic small-sized hardness tester TEMP-4 was chosen. This device met all the requirements on the decision of set tasks of research connected with express researches both laboratory and industrial conditions, and the field at the decision of tasks of fire-technical examination directly on a place of ignition of the transport unit. Experimental results of nondestructive express measuring of various metal samples are described. Metal fasteners and supporting constructions are chosen as samples for research. The thermal effect on the test specimens was carried out in a thermostat chamber allowing for an impact heating rate. The results, testifying about change of microhardness of metal products as a result of influence of a high-temperature field are received.