SEM-EDS MICROCHEMICAL ANALYSIS OF THE MnS NONMETALLIC INCLUSIONS AND METAL MATRIX INTERFACE IN THE CARBURISED 20MnCrB5 STEEL
The results of investigation of 20MnCrB5 steel for carburisation and direct quenching are given in this paper. This is very important steel for motor's industry. Beside some usual factors that affect the strength and toughnes is also demanded the carburised layer depth, carbon content (% ) on the surface of carburised steel and special fracture toughnestest for this quality of the steel. Research and explanation of SEM-EDS microchemical analysis of the MnS nonmetallic inclusions and metal matrix interface in the carburised 20MnCrB5 steel was conducted in the aim of achiving demanded special fracture toughnes.
Analysis of hardenability effect of boron
AbstractThe effect of boron on the hardenability of steels depends on the contents of such elements as aluminium, titanium, nitrogen, and boron and on the austenitising temperature. An attempt has been made to calculate the solubility of boron in the presence of aluminium, titanium, and nitrogen in steels. Three systems, Ti–B–Al–N, Ti–B–N, and B–N, were derived according to the thermodynamic state of each steel and the soluble boron contents were calculated. It was found that the maximum boron factor was achieved at 0·0004–0·0005% soluble boron. The fact that aluminium content in the range 0·018–0·050 wt-% investigated in this study has little effect on the boron hardenability factor can be explained from the results of the thermodynamic calculation.MST/1025
Tourism in the Amazon: identifying challenges and finding solutions
Purpose – The purpose of this paper is to provide an overview of the tourism sector in the Amazon regions of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, and Suriname and then discuss the manner in which tourism activity assists the protection of the Amazon rainforests. The paper also describes the manner in which the first World Hospitality and Tourism Themes Roundtable on Tourism in the Amazon is organized in 2009.Design/methodology/approach – Teams of researchers from the Ministries of Tourism, the private sector and academia in the Member Countries of Treaty for Amazon Cooperation collaborated to address, in ten‐page papers, the question “Does sustainable tourism offer solutions for the protection of the Amazon rainforest?”Findings – The paper provides valuable information on the current state of tourism policy and practice in the Amazon Member Countries. It also articulates the challenges that attend the development of sustainable tourism as a mechanism for the protection of the Amazon.Practical...