Study of densification and mechanical properties of HSLA P/M steels

Abstract

Powder metallurgy (P/M) is recognized as one of the most important manufacturing processes for making several industrial products. The production of powder metallurgy parts has been expanding at a significantly faster rate because of the advantages associated with it. The advantages include compositional flexibility, minimized segregation, ability to produce graded microstructures with varying physical and mechanical properties, quality, cost, precision, productivity, optimized material utilization, etc. The production of components from HSLA steel has been in the past through the conventional routes such as metal casting, forming and forging. Casting the metal into billets and machining the components from the billets and bringing them to standard size blocks and required shapes where energy intensive process that produced large amounts of scrap with material utility ranging from 50% to 80%. Fine machining, grinding and lapping operations made this components highly non competitive on the economic front. Keeping this in mind, in the present investigation, it is envisaged to adapt P/M route coupled with certain conventional process to produce components in close tolerance with the design. It is necessary to investigate the fundamentals, involved in preparing suitable preforms, sintering them at well specified temperature for a length of time and then forging them at newlinespecified temperature. Tests for evaluating the mechanical properties of the newlinespecimens will be performed in order to understand the constraints and newlinesuitable components can be manufactured economically. The main objective of this present research work is to develop the newlineHSLA steels. The powder mixes of HSLA steels were prepared from the newlineelemental powders such as manganese, chromium and molybdenum. Three newlinedifferent compositions of AISI 4140 steel powder mixes were mixed in a pot newlinemill for the period of 12 hours at room temperature. newline