Patents Assigned to Lydmet Limited
  • Patent number: 5573057
    Abstract: A method of producing a chilled iron camshaft from a chromium containing cast iron is described. The cast iron material contains between 0.5 wt % to 1.2 wt % of chromium. The camshaft having a white iron structure adjacent chill inserts in a casting mold and a grey iron structure in substantially all other regions remote from the chills. The method comprising the steps of assembling a sand casting mold having a camshaft shaped cavity and also having chill inserts adjacent the cavity regions where white iron is desired. Preparing a molten metal charge of cast iron having a carbon equivalent lying in the range from 3.5 up to 4.0 wt % and adding sufficient nucleant prior to pouring to fill the mold cavity, to ensure that under cooling of residual liquid remaining after solidification of the white iron structure adjacent the chills remains above the iron-cementite eutectic temperature prior to solidification into grey iron.
    Type: Grant
    Filed: March 15, 1994
    Date of Patent: November 12, 1996
    Assignee: Lydmet Limited
    Inventor: Alexander K. McDonald
  • Patent number: 5122204
    Abstract: A method of producing a chilled iron camshaft is described, wherein the iron has a white iron structure adjacent chill inserts in a casting mould and a grey iron structure in substantially all other regions remote from the chills. The method comprises the steps of assembling a sand casting mould having a camshaft shaped cavity and also having chill inserts adjacent the cavity regions where while iron is desired, preparing a molten metal charge of cast iron having a carbon equivalent lying in the range from 3.3 to 3.85 wt % and adding sufficient nucleant prior to pouring to fill the mould cavity to ensure that undercooling of residual liquid remaining after solidification of the white iron structure adjacent the chills remains above the iron-cementite eutectic temperature prior to solidfication into grey iron.
    Type: Grant
    Filed: April 2, 1991
    Date of Patent: June 16, 1992
    Assignee: Lydmet Limited
    Inventor: Alexander K. McDonald