Patent ID: 6074765
Filing Date: 2000-06-13
Classification: B02C,C21D,C22C,Y10S,Y10T

Abstract:
A grinding rod chemistry for enhancing wearability and durability of a steel rod comprises:carbon 0.70-1.00% by weight;manganese 0.60-1.00% by weight;silicon 0.10-0.40% by weight;chromium 0.25-1.04% by weight;molybdenum 0.01-0.25% by weight; andbalance essentially iron; and with the proviso that a combination of carbon, molybdenum and chromium within the above ranges are selected as follows to provide a non-bainitic core:a) at the lower 0.7% carbon with a minimum of 0.01% molybdenum, chromium is equal to or less than 1.04% and with a maximum of 0.25% molybdenum, chromium is equal to or less than 0.43%; andb) at the upper 1.00% carbon, with a minimum of 0.01% molybdenum, chromium is equal to or less than 0.80% and with a maximum of 0.25% molybdenum, chromium is equal to or less than 0.28%, said rod being characterized by:i) a core of greater than 99% pearlite having a hardness less than 45 Rockwell C;ii) an outer shell of tempered martensite having a hardness of greater than 55 Rockwell C and a uniform annular thickness greater than about 1.25 cm;iii) a 10 cm to 15 cm soft end having a hardness less than 35 Rockwell C; andiv) wherein each soft end has an intermediate portion of a hardness less than 25 Rockwell C to provide thereby a ring with improved crack arresting properties.