EFFECT OF DIFFERENT QUENCHING MEDIA ON MECHANICAL PROPERTIES OF AISI 1018 LOW CARBON STEEL

In this work, the mechanical properties of AISI 1018 low carbon steel after been treated by different quenching media (water, boiling water, boiling salt water, ice water, ice salt water) were evaluated. The microstructure of the specimen was examined by using optical microscopy (OM), while the mechanical properties were evaluated by using tensile test and hardness test. The results of this investigation showed that improving in mechanical properties such as yield strength about 580 MPa, ultimate tensile strength about 680MPa and Vickers hardness about 263.03Hv for the specimen quenching by ice water, and the hardness for ice salt water 290.8 Hv. For ice salt water quenching media, the formation of martensite phase more than another quenching media, this is revealed obviously by microstructure examination. Also retained austenite exists in as a secondary phase as a result of very fast cooling for ice salt water quenching media