Process for making wrought, lead-calcium battery grid alloy having high temperature tensile strength stability

A process for making wrought, lead-calcium, automotive, battery grids comprising the steps of:

• casting a strip of alloy consisting essentially of about 0.07% to about 0.11% by weight calcium, from 0% to no more than about 0.35% by weight tin and the balance principally lead;
• and continuously rolling said strip rapidly in one direction through a plurality of rolling stations to significantly reduce its thickness, said rolling being such as to cold work said alloy by a sufficient amount to induce strain hardening and at a sufficient rate as not to induce any significant strain aging of said strip during said rolling, and so as to yield an alloy which recrystallizes at room temperature to a substantially fine-grained structure within about 30 days of said rolling, has a 150.degree. F. tensile strength stability in excess of 1 year, and has a low susceptibility to intergranular corrosion.

A process for making wrought, lead-calcium, automotive, battery grids comprising the steps of:

• continuously casting an alloy strip consisting essentially of about 0.08% to about 0.1% calcium, about 0.2% to about 0.35% by weight tin and the balance principally lead;
• and before any significant age hardening occurs, passing said strip in one direction quickly through a plurality of serially arranged cold rolling stations and therein incrementally reducing the thickness thereof at each station by about 35% of the thickness of the strip entering said station and such that the time interval between successive stations is less than about 30 seconds so as to yield a strip is produced which substantially recrystallizes within about 30 days of said rolling, has a 150.degree. F. tensile strength stability of at least about 5500 psi for a period of at least 1 year and has a low susceptibility to intergranular corrosion.

A process for making wrought, lead-calcium, automotive, battery grids comprising the steps of:

• continuously casting an alloy strip consisting essentially of about 0.07% to about 0.11% calcium, about 0.35% to about 1.5% by weight tin and the balance principally lead;
• and before any significant age hardening occurs, passing said strip in one direction quickly through at least six serially arranged cold rolling stations and therein significantly reducing the thickness thereof in substantially equal thickness increments and such that the time interval between successive stations is less than about 30 seconds so as to yield a strip which substantially recrystallizes at room temperature within about 30 days of said rolling, has a 150.degree. F. tensile strength stability of at least about 5500 psi for a period of at least 1 year and has a low susceptibility to intergranular corrosion.