A Study of High Strength, Heat Treated Plain Carbon Steels PDF Download

Author: Ing Shing Chien
Publisher:
ISBN:
Category : Carbon steel
Languages : en
Pages : 144

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Book Description
"This work was undertaken as the initial step in a program of studying brittleness in carbon steel that has been heat treated to high strength levels. The trend in modern technology is toward higher tensile strengths. In practice, only alloy steels are commonly heat treated to very high strength levels. AISI 4340 is one of the more commonly used steels when high strength is desired. It is also becoming almost standard practice to use some of the tool steels or highly alloyed maraging steels for high strength structural components. For this study high strength in a heat treated steel is arbitrarily assumed to be 300,000 psi tensile strength. A certain minimum carbon content is probably required if 300,000 psi tensile strength is to be produced in the steel by heat treatment. Since not all heats of carbon steel are sufficiently ductile at high strength levels to permit the making of meaningful tensile test~ the major effort in this thesis project has been devoted to searching for a steel that can be used as a reference material in a study of brittleness and to developing techniques to be used in working with high strength steel. Unfortunately, the search for a reference steel has not been completely successful. However, it has been possible to heat treat round tensile test bars to tensile strengths over 300,000 psi. The procedure was relatively simple and involved no protective atmosphere or elaborate fixtures for holding the samples during the heat treatment. Machining round tensile test samples required too much care and expense. It became necessary to change to a less expensive strip type sample. Strip samples of about 250,000 psi tensile strength were prepared and tested. It is believed that the testing procedure will be satisfactory for strip samples with tensile strengths over 300,000 psi when the material is obtained. A limited amount of work has been done on the preparation of samples for transmission electron microscope studies. The procedure for making thin sections requires further refinement"--Introduction, pages 1-2.