MACHINOPT

Purpose and goal

Modification of inclusions by REM-treatment of a carbon steel and a Ca-treatment of a stainless steel was performed with the aim to improve the machinability. The goal is to increase the use of high performance steels in industrial products and components with 50% for which today the machining cost is substantial. Further is the goal to improve the fatigue strength of the carbon steel by 25% and to maintain the corrosion resistance of the stainless steel. The goals were not fully reached within the project but really good improvements in machinability was reached in the case of milling.

Expected results and effects

The modified inclusion morphology for the REM-treated steel followed the teorethical expectations very well. Unfortunately a too large addition of Ce influenced the microstructure negatively and agglomerates of inclusions ruined the expected improvement in fatigue strength. The modified inclusion morphology for the Ca-treated steel followed the theoretical calculations extremely well. An improvemd machinability was reached substantiall in milling but also in less degree for turning whereas in long-hole drilling no improvements was reached.

Planned approach and implementation

The project was divided in three stages: Stage 1 - Metallurgy, production of materials, material characterisation and verification of produced bars. Stage 2 - Machining, field tests (industrial demonstrators) and Environment-, cost- and weightreduction-analysis. Stage 3 - Recommendations for future metallurgy of the steels in the study and similar steels and to offer advice for production and cutting technology of such steels. These three stages were further sub-divided into 9 workpackages.