I’m sorry but I do not agree with a lot of responses you have recieved to coke drum cracking i.e preparation for welding etc.
Don’t close the gate after the horse has gotten out ! Look at the following; Quench cycle to address coke drum cracks, automate and modify your quenching in a regulated consistent manner to minimize cracking. For cracks at the skirt, look at your vapor heat temperature and stick to the minimum at least . Avoid swinging early. Use the right temperature indicators, not the inlet line temp. use several skin temperatures around the skirt. Also, you do not have to cut rates to optimize your drum cycles, you need to plan them. Don’t get caught in a jam with a cable change, an overhead line cleaning and be forced to modify your cycles. Do all this during a de-coke or plan all the activities together and don’t get caught with your pants down. Stuck drill stems causing you to upset your cycle and take short cuts? Use a tensioning device to avoid stems getting stuck and bird caging on stem cables. Most of the time, unless the drums are extremely old, it’s not the metallurgy, it’s how you manage it. Also, if you made a conscious decision to sacrifice the drums for throughput, it may be time to pay up. Nothings for free but at least try the above things first and when all else fails, you may have to bite the bullet.