The demand for safer and fuel-efficient vehicles leads the automotive industry to seek new and stronger materials. The steel industry, threatened by the aluminum competition, reacted with new and higher strength steels. Among the possible steels, the Advanced High Strength Steels (AHSS) can be highlighted. These steels can be divided into 3 generations, each one possessing advantages and challenges. The first generation includes more economical alloying and processing strategies, usually with a ferritic/martensitic microstructure. The second generation contains the more expensive, higher alloyed ferritic/austenitic stainless steels, using TWinning Induced Plasticity (TWIP). Between these two classes, a third generation is growing, based on more inexpensive compositions but with more complex processing, such as Quenching and Partitioning (Q and P). There is not only a single path to success, because of that, all three generations receive their fair amount of attention and research. Trying to fulfill part of the industry demand, the Companhia Siderúrgica Nacional (CSN) is conducting research on the first generation of AHSS steels. Among the first generation steels, Dual-Phase (DP) are the most used. However, DP steels present some problems, such as void nucleation during deformation, which is a limiting factor on their mechanical properties. Therefore, their replacement by Complex-Phase (CP) steels, with higher bainite amounts, and less prone to void nucleation, is welcome. The complex phase steels processing involves a sequence of hot-rolling and cold rolling steps, followed by a heat treatment. In the present thesis, the production of a CP1200 steel in an industrial hot dip galvanizing line was studied. The starting point was an industrial CP1100 steel. Samples of this cold rolled steel were analyzed by quenching dilatometry to obtain the CCT curve. Using the dilatometric data, a new heat treatment was proposed and done at CSN facilities, successfully producing a CP 1200 steel. Tension, hardness, bending and hole expansion tests were performed to measure the mechanical properties of the new steel. The microstructural characterization was done using light optical microscopy (LOM), scanning electron microscopy (SEM), atomic force microscopy (AFM), electron backscattering diffraction (EBSD) and transmission electron microscopy (TEM); neural networks and digital image processing were used to quantify the obtained micrographs. The increase in tension and yielding strengths was explained based on the higher amounts of bainite as well as of bainite-ferrite and bainite-martensite interfaces, found to be less prone to void nucleation.