A Study on Boronizing of Duplex Stainless Steel

Abstract

Boronizing is a method to increase the surface hardness of engineering components [1]. This is beneficial especially when the components are always in surface contact with other materials. In this study, boronizing treatment was successfully done on duplex stainless steel (DSS). Two types of DSS with different microstructure were boronized – the as-received DSS and the fine grain DSS. The morphology of boride layer formed on boronized DSS is compact and smooth. The boride layer thickness for both DSS ranged from 9 to 32 +m. Depending on boronizing time and temperature, the hardness of boronized fine grain DSS is between 1014 HV to 2601 HV. The values are higher than that of the as-received DSS which is between 797 HV to 2311 HV. The result shows that there is a different in hardness of boride layer for two different grain sizes of DSS although the layer thickness formed is about the same in depth.

Surface modification method of duplex type stainless steels by the pack boriding process

“…Ramakrishnan Hariharan 1 , Balasundaram Rathinam 1 , Baskar Neelakandan 2 , Radhakrishnan Beemaraj 3 i Chellamuthu Kannan 1 1 K. Ramakrishnan College of Engineering, Tiruchirappalli, Tamil Nadu, India 2 Saranathan College of Engineering, Tiruchirappalli, Tamil Nadu, India 3 Nadar Saraswathi College of Engineering and Technology, Theni, Tamil Nadu, India (Stručni rad) Ovaj rad prikazije istraživanje procesa boriranja dve vrste nerđajućeg čelika: UNS 32750 super dupleks nerđajući čelik i UNSS 31803 dupleks nerđajući čelik, u cilju poboljšanja osobina materijala i smanjenja mogućnosti katastrofalnih otkaza industrijskih komponenata. Upotreba dupleks nerđajućih čelika postala je raširena u postrojanjima za vađenje nafte i rafinerijama, u pomorstvu i u cevovodima, a zbog njihove povećane otpornosti na koroziju.…”

“…The increased mechanical strength, toughness and corrosion resistance makes these steels suitable in chloride environments [2]. These duplex and super duplex stainless steels, having increased pitting resistance [2] are applicable in the fields of oil and gas industry, marine applications, piping construction, chemical industry, and petrochemical plants [3]. Greater weldability and better mechanical properties of these steels as compared to those of austenitic stainless steels favor their usage in oil and gas refinery and chemical plants [4].…”