The surgery I did on my tree

This asian pear tree is about 5-6years old . I noticed some dark canker developing on one of the branches. I removed that branch later to prevent disease ( I later thought was the fire blight ) further spreading. I week later after I removed that branch, I saw a little dark area started on the trunk where the branch and the trunk met. I kept monitoring the development of that dark area and found it progressed very rapidly downward on the trunk. My tree didn’t have serious fire blight issue in the past, I mean, typical tip burn symptoms in the spring time, only the issues of cankers on branches here and there which some I just cut the branches off, or mostly they healed themselves ( stopped further expending the canker into larger area). But the speed of canker move down on the main trunk worries me. I am not sure if fire blight can , or usually develope in the summer /high temperature days. I don’t want other branches to be infected so I decided to remove the canker in attempting to save the rest of the tree from being infected. I carved the bark off till green color, used bleach wiped the blade every cut , and put all the cankered bark to a plastic bag and dumped in garbage. After all has been done, I disinfected entire surgery area with bleach full strength. Hope my effort will have good result. I really hate to see a healthy tree dies in fire blight.