Interstitial Free (IF) Steels Are High Formable, Low Strength Steels Used In Auto Body. In The Present Work, Classical Age Hardening Effect Of Copper In Iron Has Been Exploited To Develop High Strength Copper-Containing IF (IF-Cu) Steel In Both Hot Rolled And Cold Rolled And Annealed Conditions. Processing And Experiments Relevant To Automotive Applications Have Been Done On Different Compositions Of IF-Cu Steels And Their Properties Have Been Compared With Similarly Processed Traditional Mild IF And High Strength IF (IF-HS) Steels. Two Most Important Processing Steps, Annealing And Ageing, Have Been Studied With Conventional Techniques As Well As With The Novel Characterisation Technique Of Thermoelectric Power (TEP). Further, The Deleterious Effect Of Surface Hot Shortness (SHS) Due Copper In Steels Has Been Investigated With An Aim To Minimise It In IF-Cu Steels. Results On IF-Cu Steel Containing ~ 1.2 Wt.% Copper Show That A High Work Hardenable Hot Rolled Material With Yield Strength (YS) Of ~ 431 Mpa And Ultimate Tensile Strength (UTS) Of ~ 537 Mpa Can Be Obtained By Adopting A Low Temperature (550°C) Coiling. On The Other Hand, YS Of ~ 453 Mpa And UTS ~ 566 Mpa Can Be Achieved In The Same Steel In Cold Rolled And Continuous Annealed Condition After A Short Time Post-Annealing Ageing Treatment At 550°C. Even Higher Strength Levels Are Predicted For Ageing At 500°C. These Strength Values Are Much Larger Than Those Attainable By Traditional Methods Of Hardening IF Steels. The Formability Parameters (Lankford Parameter And Strain Hardening Exponent) Suggest That The Continuous Annealed IF-Cu Steel Can Be Press Formed Easily And Then It Can Be Subjected To The Ageing Treatment For Achieving The High Strength. The Recrystallisation Kinetics Of IF-Cu Steel Is Sluggish As Compared With Traditional IF Steels Due To The Presence Of Solute Copper And/Or Copper-Containing Precipitates In The Former. The Coiling Temperature Affects The Recrystallisation Kinetics And The Formability Parameters Through Its Effect On The State Of Copper (Solute Or Precipitate) In The As-Coiled Material. The Continuous Annealed Ifcu Steel Is Softer Than Batch Annealed IF-Cu Steel And Continuous Annealed IF-HS Steels. Its Lankford Parameter Is Higher Than Batch Annealed IF-Cu Steel And Comparable To Continuous Annealed IF-HS Steels. The Strain Hardening Exponent And The Strain Hardening Rate Of Continuous