Abstract: A process for enhancing chemical stability and corrosion resistance is described for perforated current collectors made by continuous production processes for use in electrochemical cells, including storage batteries such as lead-acid batteries. The process relies on utilizing a strip processing method, selected from the group of reciprocating expansion, rotary expansion and punching, to perforate the solid metal strip to form a grid or mesh, as a deformation treatment. The perforation-deformation treatment is followed in rapid succession by a heat-treatment to obtain a recrystallized microstructure in the current collector and optionally by quenching to rapidly reduce the temperature to below approximately 80° C. The process yields an improved microstructure consisting of a high frequency of special low &Sgr; CSL grain boundaries (>50%), exhibiting significantly improved resistance to intergranular corrosion and cracking.

Abstract: Recrystallized lead and lead alloy positive current collectors and connectors such as straps and lugs for use e.g. in lead acid batteries and electrowinning anodes, having an increased percentage of special grain boundaries in at least part of the microstructure, which have been provided by a process comprising of (i) cold or hot rolling or cold or hot extrusion or (ii) steps of deforming the lead or lead alloy, and subsequently annealing the lead or lead alloy. Either a single cycle of working and annealing can be provided, or a plurality of such cycles can be provided.

Abstract: A surface treatment process for enhancing the resistance to intergranular corrosion and intergranular cracking of components fabricated from austenitic Ni—Fe—Cr based alloys comprising the application of surface deformation to the component, to a depth in the range of 0.01 mm to 0.5 mm, for example by high intensity shot peening below the recrystallization temperature, followed by recrystallization heat treatment, preferably at solutionizing temperatures. The surface deformation and annealing process can be repeated to further optimize the microstructure of the near-surface region. Following the final heat treatment, the process optionally comprises the application of further surface deformation (work) of reduced intensity, yielding a worked depth of between 0.005 mm to 0.01 mm, to impart residual compression in the near surface region to further enhance cracking resistance.

Abstract: A process for enhancing chemical stability, corrosion resistance and for improved adhesion characteristics is described for use on metal or metal-alloy non-consumable electrodes, current collectors or other metallic articles used in electrochemical cells. The process includes peening of the article, optionally followed by an annealing treatment.

Abstract: Recrystallized lead and lead alloy positive current collectors and connectors such as straps and lugs for use e.g. in lead acid batteries and electrowinning anodes, having an increased percentage of special grain boundaries in at least part of the microstructure, which have been provided by a process comprising of (i) cold or hot rolling or cold or hot extrusion or (ii) steps of deforming the lead or lead alloy, and subsequently annealing the lead or lead alloy. Either a single cycle of working and annealing can be provided, or a plurality of such cycles can be provided.

Abstract: A surface treatment process for enhancing the resistance to intergranular corrosion and intergranular cracking of components fabricated from austenitic Ni—Fe—Cr based alloys comprising the application of surface deformation to the component, to a depth in the range of 0.01 mm to 0.5 mm, for example by high intensity shot peening below the recrystallization temperature, followed by recrystallization heat treatment, preferably at solutionizing temperatures. The surface deformation and annealing process can be repeated to further optimize the microstructure of the near-surface region. Following the final heat treatment, the process optionally comprises the application of further surface deformation (work) of reduced intensity, yielding a worked depth of between 0.005 mm to 0.01 mm, to impart residual compression in the near surface region to further enhance cracking resistance.

Abstract: A surface treatment process for enhancing the intergranular corrosion and intergranular cracking resistance of components fabricated from austenitic Ni—Fe—Cr based alloys comprised of the application of surface cold work to a depth in the range of 0.01 mm to 0.5 mm, for example by high intensity shot peening, followed by recrystallization heat treatment preferably at solutionizing temperatures (>900 C.). The surface cold work and annealing process can be repeated to further optimize the microstructure of the near-surface region. Following the final heat treatment, the process can optionally comprise the application of surface cold work of reduced intensity, yielding a cold worked depth of 0.005 mm to 0.01 mm, in order further enhance resistance to cracking by rendering the near surface in residual compression.