Grain size, as one of the key factors affecting the performance of titanium rods, has a significant impact on their mechanical properties and corrosion resistance. Grain size describes the size and distribution of internal grains in titanium rods, which directly affects their strength, plasticity, toughness, and corrosion resistance.

1. Grain size affects the strength of titanium rods. Grain refinement can increase the number of grain boundaries, effectively disperse stress, and thus improve the tensile strength and yield strength of products.

2. The grain size also has a significant impact on the plasticity of titanium rods. Small grains mean more grain boundaries, which can accommodate more dislocations during plastic deformation, thereby improving the elongation and toughness of the product.

3. The grain size is also closely related to the corrosion resistance of titanium rods. Grain refinement can reduce the potential difference at grain boundaries, reduce corrosion sensitivity, and thus improve the corrosion resistance of products. Especially in harsh environments such as strong acids and alkalis, the grain size requires higher corrosion resistance of the product.

Therefore, in the production process of titanium rods, controlling grain size is an important means to improve the performance of titanium rods. By using reasonable heat treatment processes, adjusting alloy composition, and other methods, the grain size of the product can be optimized, thereby improving its comprehensive performance and meeting the application needs of different fields.