Is welding on crossbeams 'acceptable'?

I have an old Marstrøm rearbeam with some cracks lying in my basement, begging for action on another boat. Should be easy to weld if it's 'acceptable'. The integrated traveller pulled off and some other stress-cracks began to form. I psyched out and replaced it.
I was worrying that the heat would change the properties of the surrounding material and make it a weak point?


Tought I should ask when the topic was raised..