Preface to the First Edition

During the recent and solemn commemoration of the 50th anniversary of this Instituto de Pesquisas Tecnológicas [Technological Research Institute], the beginning and the further development of various technological sectors of the institute were remembered. Among these, the field of microscopic metallography has received deserved attention; having started almost at the same time as this field was developed in Europe, it is one of the oldest in the institute.

It is an important fact that in 1910, the head of the Office of Strength of Materials, Hippolyto Pujol Jr., was already teaching and applying in the country such a novel science, far in advance of our industrial development. In 1926, it was up to Ary Frederico Torres to give further drive to these studies, creating strong interest and promoting the specialization of many students from the Polytechnic School [today the Polytechnic School of the University of São Paulo]. The author of this volume was among those and in 1928 was raised to the position of head of the Metallography Section.

In the past 25 years, the application and research work performed in the Metallography Section of IPT has resulted in a very refined technique and precise documentation with more than 10,000 macrographs and micrographs.

In addition to these activities, focused on the industrial segment, the Metallography Section has paid special attention to education, either teaching the students in various courses of the Polytechnic School or opening opportunities for interns who come here in search of deeper knowledge.

Among the educational resources, one that has been extremely successful is the distribution of illustrated pamphlets condensing the subjects presented in class. The simple and accessible presentation, not only of the metallographic technique but also of the laws and basic metallurgical facts—indispensable to the understanding of metallography and useful to the steel industry—quickly garnered great interest. This intertwining of steelmaking and processing concepts with specialized metallographic concepts may seem strange at first, but at least in our community and for the time being, this is the orientation that has proven most efficient for the desired objectives.

After various successive editions of these pamphlets, and faced with an ever-increasing demand and the growing collection of experiments, the institute has decided to publish its material in a more permanent form and in more copies, asking the author himself to collect them, after revision and considerable expansion of the illustrations, in a printed volume that came to be the present bulletin.

Maintaining the initial aim, certain theoretical concepts are presented in a simplified way while others are omitted, not because they are useless but because they can be dispensed of in view of the character and aim of this publication.

To those wishing to research the problem more deeply, the cited bibliography, however small, offers additional information. After the bibliography, the conference proceedings and the specialized journals are yet additional sources which the reader can make use of to get properly familiarized with this constantly evolving science.

The macrographs and micrographs that were reprinted in Bulletin no. 40 were selected as among the most significant cases studied in the section. For each type of occurrence, many examples were presented to illustrate the variability that certain aspects may present and to warn the less experienced metallographer about the risk of possible confusion. In the choice and presentation of this vast documentation, it was our intention to offer to those interested a real atlas of “standard aspects” that could help in interpreting cases one might face in practice. Furthermore, there was always the aim of presenting the original documents in the best way possible, without reduction and with maximum sharpness, to make it easier for the reader to properly appreciate the features in the structures.

In the course of the text, the main errors related to technique and interpretation are discussed, along with their consequences and how to avoid them.

With the goals above described, the Instituto de Pesquisas Tecnológicas hopes to have extended the usefulness of this publication to all, whether in the plant or in the laboratory, who apply metallography.