Steel strapping and method of making
AssigneeIllinois Tool Works Inc.
InventorsJeffery W Doonan, Peter Ivan Unicomb, Robert K Armstrong
Life of this patent
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Abstract
Steel strapping and a method of manufacturing steel strapping are disclosed. The steel strapping has the following composition in wt % and a microstructure including a matrix of recovery-annealed cold worked ferrite containing martensite and carbides dispersed through the matrix. C: up to 0.2 Mn: up to 2.0 Si: 0.2-0.4 Ti: 0.025-0.045 V: 0.05-0.07 Cr: up to 0.25 Ni: up to 0.30 Mo: up to 0.10 N: up to 0.005 Cu: up to 0.20 Al: up to 0.08 Nb: up to 0.005 P: up to 0.035 S: up to 0.020 Balance iron and incidental impurities.
Claims15
A steel strapping having the following composition in wt % and a microstructure including a matrix of recovery-annealed cold worked ferrite containing martensite and carbides dispersed through the matrix
- C:
- up to 0.2 Mn:
- up to 2.0 Si:
- 0.2-0.4 Ti:
- 0.025-0.045 V:
- 0.05-0.07 Cr:
- up to 0.25 Ni:
- up to 0.30 Mo:
- up to 0.10 N:
- up to 0.005 Cu:
- up to 0.20 Al:
- up to 0.08 Nb:
- up to 0.005 P:
- up to 0.035 S:
- up to 0.020 Balance iron and incidental impurities.
A method of manufacturing steel strapping which includes the steps of:
- (a) hot rolling steel slabs by passing the slabs through a series of rolling mill stands in a hot strip mill and reducing the slab thickness to form steel strip;
- (b) cold rolling the steel strip in a cold rolling mill and reducing the thickness of the strip;
- and
- (c) heat treating the steel strip to produce steel strapping,
- the method being characterized by selecting the hot rolling conditions and the steel slab composition so that there is recrystallisation of steel in each stand of the hot rolling mill, and
- wherein the strapping produced by the method has a microstructure comprising a matrix of recovery annealed cold worked ferrite containing martensite and carbides dispersed throughout the matrix.
A method of manufacturing steel strapping which includes the steps of:
- (a) hot rolling steel slabs by passing the slabs through a series of rolling mill stands in a hot strip mill and reducing the slab thickness to form steel strip;
- (b) cold rolling the steel strip in a cold rolling mill and reducing the thickness of the strip;
- and
- (c) heat treating the steel strip to produce steel strapping,
- the method being characterized by selecting the hot rolling conditions and the steel slab composition so that there is recrystallisation of steel in each stand of the hot rolling mill, and
- wherein heat treatment step (c) includes:
- (i) rapidly heating the strapping to the dual phase temperature range using induction heating, with little or no soaking, and
- (ii) rapidly cooling the strapping.
Dependencies are inferred from the claim text.