EP 0297024 B1 19910731 - METHOD FOR HARDENING A HOLLOW ARTICLE
Title (en)
METHOD FOR HARDENING A HOLLOW ARTICLE
Publication
Application
Priority
DE 3721665 A 19870626
Abstract (en)
[origin: US4900376A] A method for hardening cylindrical hollows made of steel, includes heating followed by cooling, under utilization of a water bath while the hollow rotates about its longitudinal axis, and is partially immersed in the bath, the axis being parallel to the surface of the cooling bath; this method is improved by providing a particular rotation for the hollow as long as the temperature of the hollow is above the martensitic starting temperature; and drastically increasing the speed of rotation such that a significantly higher speed obtains as the martensitic transition temperature is reached.
IPC 1-7
IPC 8 full level
C21D 1/18 (2006.01); C21D 1/63 (2006.01); C21D 9/08 (2006.01); C21D 9/40 (2006.01)
CPC (source: EP US)
C21D 1/63 (2013.01 - EP US); C21D 9/085 (2013.01 - EP US)
Designated contracting state (EPC)
AT ES FR GB IT
DOCDB simple family (publication)
US 4900376 A 19900213; AT E65802 T1 19910815; CA 1310891 C 19921201; DE 3721665 C1 19880414; EP 0297024 A1 19881228; EP 0297024 B1 19910731; ES 2023712 B3 19920201; JP H048487 B2 19920217; JP S6417822 A 19890120
DOCDB simple family (application)
US 21007788 A 19880622; AT 88730110 T 19880510; CA 570439 A 19880624; DE 3721665 A 19870626; EP 88730110 A 19880510; ES 88730110 T 19880510; JP 14668488 A 19880614