7075—T651合金厚板预拉伸断裂原因分析

Analysis of the Cracks Causes for Pre-stretching Plates of 7075 T651 Alloy

分析了７０７５－Ｔ６５１合金厚板预拉伸断裂的原因。７０７５－Ｔ６５１合金厚板拉伸断裂的表现形式为断口的一侧存在三角裂纹。经研究认为方锭中心有严重疏松带，在热轧变形过程中因边部和中心层变形不均，未被焊合的疏松形成隐形裂纹并随轧制的进行扩展所致。

The crack causes for pre-stretching plates of 7075 T651 alloy are analysed. The crack form of 7075 T651 plates is the triangle crack on one side of the gap. The test results show that porosity strip exists in the central of the slab. During the deformation of hot rolling, the un-welded porosity forms hidillg crackles because the out and central layers are uneven deformed. When the rolling goes on, the crackles develop and result in the crack.