THE STUDY CONDITIONS OCCURRENCE OF HOT TEARING IN THE BILLETS ALLOY EN AW6060 PRODUCED WITH THE PROCESS OF DIRECT CHILL CASTING

摘要

During Direct Chill casting of aluminum alloys technology Wagstaff AirS lip, the primary and secondary cooling causes strong thermal gradients, which leads to the uneven thermal contraction in different sections of the billet. The consequences are manifested appearance of casting defects such as hot tearing and residual stresses. In order to reduce the occurrence of these defects were studied different effects on the formation of hot tearing: changes of technological parameters, chemical composition and microstructure of the alloy EN AW 6060 according to the length and cross section, and the conditions of occurrence and progression of cracks describes the model the ratio of light and heavy metals in the billet. Additional testing of as - cast, cracked and homogenized sample billets in multiple directions cross-section detects that the rapid cooling of the surface of the billet affect the development of fields measured hardness.