It is concluded that the main causes of cracks on the gooseneck are excessive angle of inclination at LP ammonia liquor spray nozzle,graphite deposited in the gooseneck,which needs to be frequently removed,as well as much impurities in the ammonia liquor.A new LP ammonia liquor spraying device can lower the gooseneck temperature,reduce the free space temperature on oven top to extend graphite cleaning intervals and improve the troubleshooting in case of PROven system failure,which can remarkably minimize the cracking on the gooseneck.Finally,cold welding process by manual arc welding is adopted to repair the gooseneck cracks and the result is satisfactory.