If the second script is launched from the first, you can use
export to make the variable available to all the processes launched from the first script, e.g.
Code:
#!/bin/bash
echo -e "Number of Recursion step\nThe default value is 30"
read nrec
export nrec=$nrec
/path/to/second_script.sh
in this case the second script inherits the variable nrec from the environment.
Instead, if the two scripts are launched separately, I think the only way is that the first script writes the value of nrec somewhere in a file and the second script waits for the file creation and then read the value of nrec (and eventually deletes the file).