ok listen to me.
u can weld a blade or pro fork on there bu it would be piontless cuz there thin as shit and weak as shit.
what u need to do is do what aj told u get this pipe
http://www.onlinemetals.com/merchant.cfm?pid=7341&step=4&showunits=inches&id=250&top_cat=0 and if u get two feet it will be a total of 26 dollars i just bought it three weaks ago. then u cut ur fork tube wherever u want. (i asked andrew and scooterperu and they said do it like an inch below where it cracked) so i wouldnt do it at the top cuz that is where it is likely to break. then u cut ur fork tube that is connected to the fork and get it as straight as u can. then u take it to a pro and tell them u need it welded and give them a bearing cup(the cup that the bearings run on) and then tell them to make a tig weld as smooth as possible, grinding iit little as possible. so yea then ur done.
there is another way to do it but im not writing it cuz u wont listen to me that way and its even more complicated. but the way i just told u will do just fine.