Usinabilidade de aços inoxidáveis martensíticos aplicados na indústria de petróleo

Abstract

The increasing use of more and more corrosion-resistant materials, and components applied in the oil industry, makes the metals industries need to develop new materials that combine good corrosion resistance with strength, such as stainless steels. Since several components used in the oil industry are produced by machining, each new developed steel needs to be characterized in terms of manufacturing, with the aim of helping the users to render the machining process more economical. In the present work the machinability of the S410000 martensitic stainless steel and of the S41426 super-martensitic stainless steel grades were determined, both widely used in the oil industry. The machinability was raised in terms of machining forces, tool lives (expanded Taylor s equation), cutting temperatures, surface roughness and analysis of the swarf. The results allowed comparisons between the two steels studied. Generally, the S410000 steel grade provided higher machining forces, due to the larger shear deformations occurring in the perceived by measuring the degree of discharge plane. The larger forces required also influenced poorer surface roughness in relation to the S41426 steel. In terms of tool life, the super-martensitic stainless steel did not performed well under high cutting speeds. This steel also presented lower temperatures at the tool-chip interfaces than its counterpart. The results are very important for the oil industry that uses the steels investigated and for the steel companies that produced them.