Tulisan ini menyajikan ketahanan aus abrasi baja tahan karat martensit 13Cr dan modifikasinya. Sebanyak empat jenis modifikasi 13Cr stainless steel dipersiapkan untuk dilakukan proses peleburan secara induksi dan kemudian di cor menjadi ingot balok. Setelah melalui proses pengecoran, masing-masing ingot tersebut dilakukan proses tempa panas (hot forging) dan proses perlakuan panas pendinginan cepat (quenching) serta tempering. Empat jenis sampel baja tersebut dilakukan uji abrasi di bawah kertas amplas no. 120 dengan kecepatan putar 100 rpm pada pembebanan 100, 500 dan 1000 g, dan dengan jumlah putaran 100, 300, 500, 700 dan 1000 putaran. Hasil pengujian menunjukkan bahwa sifat ketahanan aus abrasi yang paling tinggi terdapat pada sampel baja tahan karat martensitik 13Cr3Mo3Ni dengan nilai kehilangan berat 43,13 mg/cm² dan kekerasan 47,5 HRc. Sedangkan sifat ketahanan aus abrasi yang paling rendah terdapat pada sampel baja tahan karat martensitik 13Cr dengan nilai kehilangan berat 63,87 mg/cm² dan kekerasan 47,7 HRc. AbstractThe several components of steam turbine like the stator and rotor blade suffer from various kind of wearcaused by solid particle erossion during turbine running. This paper presents the wear abrasion resistance of13Cr martensitic stainless steel and its modifications. Four types of modification of 13Cr stainless steel isprepared with induction melting process and then cast into ingot molds. After casting process, each of ingotis conducted hot forging process followed by quenching and tempering process. Then the four type ofstainless steel were conducted abrasion test against 120 SiC grinding paper, speed 100 rpm, load 100, 500and 1000 g, and cycle 100, 300, 500, 700 and 1000 cycles. The results show that the higher wear abrasionresistant was found in the 13Cr3Mo3Ni martensitic stainless steel with weight loss of 43.13 mg/cm² andhardness of 47.5 HRc. The lower wear abrasion resistant was found in the 13Cr martensitic stainless steelwith weight loss of 63.87 mg/cm² and hardness of 47.7 HRc.