The Influence of Heat Treatment Parameters on the Cracks Growth under Cyclic Bending in St-Ti Clad Obtained by Explosive Welding

• Main Authors: Dariusz Rozumek, Grzegorz Kwiatkowski
• Format: Article
• Language: English
• Published: MDPI AG 2019-03-01
• Series: Metals
• Subjects: explosive welding; bimetals; microstructure; fatigue crack growth
• Online Access: http://www.mdpi.com/2075-4701/9/3/338

The current work focuses on the effect of time and temperature of annealing on the change in the structure and cracks growth and fatigue life of the steel-titanium bimetal obtained by explosive welding. Cyclic bending tests were performed for different levels of annealing temperature on bimetal specimens of a rectangular cross-section. The fatigue crack growth was measured by microscopy. Structure changes of steel, titanium and bond area resulted in a different micro-hardness distribution. The relationship between the level of the annealing temperature, the propagation of fatigue cracks, structure changes and micro-hardness level is analyzed. The heat treatment of the bimetal at the temperature of 500 °C does not result in considerable changes in the structure of steel and titanium. The diffusion of carbon to titanium was observed. A higher annealing temperature results in a lower fatigue life. Also, for a given annealing temperature, a longer annealing time results in a higher fatigue life.