Ultra-high carbon steel used for production of motor vehicle parts contains alloying additions of aluminum, chromium, silicon and tin

摘要

#CMT# #/CMT# Density-reduced ultra-high carbon steel contains (wt.%): carbon (0.8-2.5), aluminum (3.5-15), chromium (0.5-4), silicon (0.01-4), nickel, manganese, molybdenum, niobium, vanadium and/or tungsten (0-4), tin (0.1-0.85) and titanium, beryllium and/or gallium (0-3). #CMT# : #/CMT# An independent claim is also included for the production of superplastic ultra-high carbon steel as above by subjecting the molten steel to a cooling process resulting in a two-phase structure with 65-85 vol.% alpha-ferrite and 15-25 vol.% kappa-carbide and cementite. #CMT#USE : #/CMT# The steel is used for making motor vehicle parts, especially engine and transmission parts (claimed). #CMT#ADVANTAGE : #/CMT# The steel has superplastic properties with minimal mill scale formation and a low density. #CMT#METALLURGY : #/CMT# Preferred Steel: The tin content is 0.3-0.5%. The aluminum content is 10-14%. The titanium content is 1.5-3% and the total titanium, beryllium and gallium content is no more than 3%. The aluminum content is more than 10%, the silicon content is more than 2% and the tin content is more than 0.5%.