INVESTIGATION OF TRANSIENT NUCLEATE BOILING PROCESSES AND THEIR PRACTICAL USE IN HEAT TREATING INDUSTRY

Abstract

In the paper transient nucleate boiling process is widely discussed. It’s unknown previously and investigated by author characteristics create a basis for designing of new technologies which allow receiving super strengthened materials. Obtained results are also used for appropriate software development to be widely applied for control of technological processes and cooling recipes design. A possibility of transition from real heat transfer coefficients (HTCs) to effective HTCs is discussed in the paper too. It is shown that core temperature of steel parts at the end of transient nucleate boiling (self-regulated thermal process (SRTP)) is a linear function of a part dimension when convective heat transfer coefficient during quenching in liquid media is fixed. Also, it is shown that effective Kondrtajev number Kn is a function of part size and convection intensity and is almost linear function for large sizes of steel parts. Surface temperature at the beginning of self-regulated thermal process and at its end is calculated depending on size and intensity of cooling. Based on obtained new results, it is possible to design DATABASE for liquid quenchants using standard Inconel 600 probe combined with the Liscic/Petrofer probe. Obtained results can be useful for engineers and software designers.