چکیده مقاله
In the present work, two kinds of steel powder were Distaloy HP 1 & Ultrapac LA selected and subjected to powder metallurgy processing For Ultrapac LA a heterogeneous microstructure consisting of tempered martensite, nickel rich ferrite, divorced pearlite and nickel rich regions surrounding pores is observed For Distaloy HP 1, in slow cooling rates 0 4 °C s 1 the amounts of martensite and bainite varies between 50 60% and 30 40% , however, for fast cooling rates 1 2 °C s 1 the variation is between 70 80% and 10 20% The mechanical properties of the prepared samples were studied with controlled production conditions such as cooling rate and heat treatment Increasing porosity plays an important role in the tensile stress and fatigue strength The ultimate tensile strength and fatigue strength were more than 1000 MPa and 400 MPa in this research for Distaloy HP 1, 7 2 g cm 3, 0 5% carbon content and fast cooling rates Macroscopic examination of the fracture surfaces for all specimens revealed that fatigue crack growth and final fracture regions were brittle and without noticeable permanent deformation The final fracture regions for all tests were very similar, final fracture in these two material conditions revealed brittle macrobehaviour and ductile microbehaviour
کلیدواژهها
نویسندگان
H Khorsand
Assistant Professor of Mechanical Engineering, Department Materials Group of Khajenasir Universityof Technology, Materials Research Center of SAPCO, Tehran, Iran
S.M Habibi
M Sc of Department of Materials science and Eng , Shiraz University TOPCO, Tehran, Iran
H Rahmani S.
Materials Research Center of SAPCO, Tehran, Iran
A Arvand
Mashad Powder Metallurgy Co
شیوه ارجاع
Khorsand, H and Habibi, S.M and Rahmani S., H and Arvand, A,1384,Investigation of Manufacturing Conditions of Powder Metallurgy Parts with Control of Microstructure and Mechanical Properties,01st Tehran International Congress on Manufacturing Engineering (TICME2005),Tehran
ارائهشده در
مجموعه مقالات اولین کنفرانس بین المللی و هفتمین کنفرانس ملی مهندسی ساخت و تولید1 فروردین 1384 · تهران