Usually it is best to replace cracked and broken parts with new parts.
It may not be practical to replace the main frame or deck on your unit. The cracked or broken part may not be available if it is for an older machine.
We can weld cracks on the frame or deck. We can weld broken steel parts. We do not have any welding certifications, we just fix what we can. Some riding mowers have a common frame cracking problem where the transaxle attaches to the frame. We have had good results with welding these, and our customers have been very happy with the results and the low cost.