Kegagalan patah, banyak dijumpai pada poros roda belakang truk. Hal ini disebabkan oleh kualitas jalan dan regulasi yang mengaturnya. Keggalan ini  berimplikasi terhadap meningkatnya jumlah limbah poros roda belakang truk. Prinsip pengelolaan limbah, repair memungkinkan penggunaan kembali limbah poros roda belakang dengan perbaikan dan perlakuan pada limbah. Proses penyambungan pada limbah poros menggunakan pengelasan gesek, menyebabkan perbedaan struktur mikro dan nilai kekerasan pada logam paduan hasil pengelasan.

Melihat fenomena di atas peneliti ingin mengetahui pengaruh perlakuan panas quenching–tempering terhadap kekuatan tarik, kekerasan dan struktur mikro pada poros hasil repair, dan untuk mengetahui perbedaan nilai sifat mekanik rear axle shaft repair dengan rear axle genuine 7.5 ton.

Metode penelitian ini menggunakan metode eksperimen dan teknik analisis data one way anova. Hasil penelitian menunjukkan quenching-tempering berpengaruh secara signifikan, pada  kekuatan tarik, kekerasan dan struktur mikro poros hasil repair pengelasan gesek. Spesifikasi mekanik repair rear axle shaft mempunyai nilai kuat tarik melebihi spesifikasi mekanik rear axle shaft genuine 7.5 ton, tetapi nilai kekerasan dan elongasi masih dibawah rear axle shaft genuine 7.5 ton.

Kata kunci:     poros roda belakang, quenching-tempering, repair, friction welding

Failure is broken, often found on the rear axle of the truck. This is caused by the quality of the road and the regulations that it stipulates. This failure has implications for the amount of truck rear axle waste. The principle of waste management, repair allows reuse of the rear axle with repair and maintenance on waste. The connection process on shaft flow uses friction welding, causing differences in the microstructure and the value of the opposition to the welded alloy metal.

Seeing the above phenomenon, the researcher wants to find out how to improve quenching - tempering heat against tensile strength, hardness, and microstructure on the improved shaft, and to find out the difference in mechanical properties of the rear axle repair with the original 7.5 ton rear axle. This research method uses one way ANOVA research methods and data analysis techniques.

The results showed that quenching-tempering had a significant effect on the tensile strength, hardness, and microstructure of the shaft resulting in improved friction welding. Mechanical specifications for rear axle improvement have tensile strength values ​​exceeding the original 7.5 tons rear axle mechanical specifications, but the point of hardness and elongation are still below the original 7.5 tons rear axle.

Keywords: rear axle shaft, quenching-tempering, repair, friction welding