Author: George Joseph Vytanovych
Publisher:
ISBN:
Category : Carbon steel
Languages : en
Pages : 152
Get Book Here
Book Description
"Methods of preparing foils of high strength, heat treated, plain carbon steels for examination in the electron microscope by the transmission technique were perfected and are described. Two processes for the initial thinning of a bulk sample were successful. A chemical process was found to be more rapid but not satisfactory for small samples. A mechanical process was slower, but was applicable to the smaller specimens. Electro-polishing the thinned material yielded acceptable foils from which photomicrographs of good quality were obtained. The microstructure of the high strength steel samples showed typical tempered martensite. No reasons for the differences in ductility of different heats of steel or for the differences in ductility of a given steel, when heat treated differently, were found"--Abstract, leaf ii.'
Author: Ing Shing Chien
Publisher:
ISBN:
Category : Carbon steel
Languages : en
Pages : 144
Get Book Here
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.
Author: John Henry Bucher
Publisher:
ISBN:
Category : Steel
Languages : en
Pages : 310
Get Book Here
Book Description
Author: M. R. Jackson
Publisher:
ISBN:
Category : Carbides
Languages : en
Pages : 12
Get Book Here
Book Description
The structure of a 1.40 weight per cent carbon steel during the first stage of tempering (up to 200 C) was studied by transmission electron microscopy. Distributions consisting of either randomly arranged spherical or aligned platelike carbide particles were observed after tempering at 150 C. The origin of both of these types of distributions can be explained by heterogeneous nucleation on and growth of carbide particles along the dislocation networks of the tempered martensite.
Author: PR. Howell
Publisher:
ISBN:
Category : Copper precipitates
Languages : en
Pages : 13
Get Book Here
Book Description
Transmission electron microscopy (TEM) together with scanning electron microscopy (SEM) and optical microscopy have been employed to analyze the microstructures that develop in a copper-containing, low-carbon (0.04% by weight) HSLA-100 alloy. Specifically, the martensitic microstructures that develop in the simulated, coarse-grained heat-affected zones (HAZs) have been examined and compared with those that develop in the base plate during conventional quenching from the austenitic phase field. It has been shown that the lath martensitic packet size is increased dramatically in the HAZ as compared with the base plate. In addition, considerably more retained austenite is found in the HAZ. No evidence for the so-called granular bainite microconstituent has been found in either material. However, for cooling rates somewhat less than that experienced in the coarse-grained HAZ, a microconstituent that we term granular ferrite has been documented.
Author: A. Phillips
Publisher:
ISBN:
Category : Alloys
Languages : en
Pages : 486
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 536
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 554
Get Book Here
Book Description
Author: United States. Energy Research and Development Administration
Publisher:
ISBN:
Category : Medicine
Languages : en
Pages : 756
Get Book Here
Book Description
Author: United States. Energy Research and Development Administration. Technical Information Center
Publisher:
ISBN:
Category : Force and energy
Languages : en
Pages : 962
Get Book Here
Book Description
