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This study adopts the application of the electrodischarge machining (EDM) hole-drilling method to the measurement of residual stress in AISI D2 cold work tool steel, AISI H13 hot work tool steel, and AISI 1045 medium carbon steel. A calibration procedure based on the thermal conductivity of the material is conducted to compensate for the additional compressive stress induced in the workpiece by the EDM hole-drilling operation. Since the formation of this white layer influences the magnitude of the induced stress, the scanning electron microscopy, transmission electron microscopy, and nanoindentation techniques are used to examine the microstructure and hardness of the white layer resolidified on the EDMed surface. The experimental results reveal that combination of the hole-drilling strain-gage method (ASTM standard E837) with an EDM drilling process provides the effective means of determining the residual stress in materials with high hardness and good wear resistance.

Measurements of residual stress on the 57Fe25Cr15Ni steel plate with no-filler TIG-welding process were carried out. This work was conducted to determine the nature of weld ability in synthesized steel. The bulks were formed in a dimension of 30x20x7 mm 3 to ease data retrieval. Results show that the largest residual stress occurred in the weld metal area, amounting to 82.40 MPa with lattice stretching of 0.18%. Conversely, the values decreased to 65.92 MPa and a stretch of 0.14% in the HAZ area. This residual stress is a tensile stress that can reduce the mechanical strength of the material since it adds to the applied loads. This was confirmed by microstructure observations. The carbon content was very high in the dark lines. Weaken materials usually start from this side and could initiate the intergranular cracks that rapidly migrate among its grain boundaries. Abstrak Pengukuran Tegangan Sisa pada Sambungan Las-TIG Bahan Struktur Baja Austenitik 57Fe15Cr25NiMenggunakan Teknik Difraksi Sinar-X. Pengukuran tegangan sisa pada pelat baja 57Fe15Cr25Ni akibat proses pengelasan TIG tanpa filler telah dilakukan. Pekerjaan ini dilakukan untuk mengetahui sifat mampu las dari bahan pelat baja. Bahan 'bulk' dibentuk plat dengan dimensi 30x20x7 mm3 untuk memudahkan pengambilan data. Hasil penelitian menunjukkan bahwa tegangan sisa terbesar terjadi di daerah pusat las, sekitar 82,40 MPa dengan kisi peregangan 0,18% dan turun pada sekitar 65,92 MPa dengan regangan sebesar 0,14% di daerah HAZ. Tegangan sisa ini adalah tegangan tarik yang dapat mengurangi kekuatan mekanik material karena mampu menambah beban terpakai. Hal ini ditegaskan dengan pengamatan mikrostruktur. Kandungan karbon sangat tinggi di garis hitam. Pelemahan bahan biasanya dimulai dari sisi ini dan bisa mengawali retakan intergranular, yang dengan cepat dapat bermigrasi di antara batas butirnya.