« PreviousContinue »
economically feasible and one can hardly be sure of the attainability of long life in view of the facts:
(1) Salt spray is present at airports near the ocean (New York, Boston, Los Angeles, San Francisco);
(2) Titanium stress corrodes rapidly in contact with NaCl at 650° F.; and
(3) Skin temperature at mach 3 is greater than 550° F. In the case of water desalination, flash distillation is used and metals are therefore needed for good heat transfer. The brine being handled is at temperature of greater than 280° F. and this is rough treatment for materials. Cheap materials last 1-3 years, and even expensive ones are uncertain. Plantlife is a critical element in the economics of the process. There are a number of questions that need answering:
(1) What are the lifetimes of expensive materials? (2) Can the cheap materials be improved ?
(3) What is rate of corrosion as determied by in situ measurements ?
(4) Are there any new improved materials? If one examines the annual Federal corrosion research budget, he finds it amounts to $8 million. This is split as follows:
Millions Department of Defense
1.1 Commerce Department..
.25 Interior Department
1.0 Today, corrosion research is largely unsophisticated, unadaptable, and uncoupled. It is unsophisticated in that the new physics and chemistry are not being used. It is unadaptable in that most of the basic research being done is not germane to the real corrosion problems as they arise in actual practice. It is uncoupled because there is little contact between the corrosion research underway and the engineering and testing of products that are experiencing corrosion. Moreover, corrosion research is hampered by a poor image; it has none of the glamour of laser or space research. This poor image contributes strongly to there being little university research. And this, in turn, results in few new people being trained.
Many efforts have been made to improve the above situation but they have been unsuccessful. One can cite several examples:
Corrosion Research Council is one where the support was from industry; however, there was never more than $50,000 in 1 year.
The Center for Prevention of Deterioration was another approach that was undertaken with Government support. It had no research expertise to keep it vitalized.
The Inter-Society Corrosion Coordinating Committee, formed with help of the technical societies, had practically no funds and no research arm to implement its ideas.
But now as never before, corrosion problems are more severe and are more difficult because of our increasing use of: (1) Very high temperatures and pressures, (2) nuclear and solar radiation, (3) exotic chemical mixtures, and (4) a combination of severe “normal” environments in our long military supply lines.
Recent scientific advances, however, have now provided us with an opportunity to solve these problems. There has been an advance in achieving ultraclean systems. Thus in 1945 a surface could be kept clean for only 1 second in a vacuum system. Now, however, in 1966, surfaces keep clean in vacuum for 1 year. Observations can now be made at atomic level. Since 1960, field ion emission microscopy and low-energy electron diffraction have made great strides.
It was proposed that there be a focusing of the national corrosion effort in which the needs and opportunities are joined. The focus would provide ways to:
(1) Apply the latest scientific knowledge to the solution of real corrosion problems;
(2) Develop methods and criteria for evaluating corrosion resistance;
( (3) Make available evaluated data on corrosion resistance;
(4) Study the economic aspects of corrosion problems; and
(5) Stimulate relevant research and development in Government and private laboratories. It would also:
(1) Train corrosion scientists and engineers in latest techniques;
(2) Offer consulting and advisory services to Government agencies;
(3) Serve as an information center in the field of corrosion; and
(4) Couple Government research to that in the private sector. The National Bureau of Standards' Institute for Materials Research was proposed as the logical place for focusing the national corrosion effort because
(1) Its acknowledged leadership in corrosion research;
(2) It is able to attract good scientists (in contrast to most organizations that have engaged in corrosion research);
(3) It is an interdisciplinary laboratory of the kind needed to solve the many problems that arise;
(4) It is associated with the clearinghouse which is in touch with all Government research results;
(5) It has competence in technical-economic analysis which is often a deciding factor in the selection of alternate solutions; and
(6) It has several coupling mechanisms with the private sector of U.S. research. Today's NBS-IMR corrosion program offers a nucleus for a corrosion center encompassing the whole corrosion spec
trum, from the very basic end of the spectrum to the applied end: Elementary reactions, thin films, stress corrosion, galvanic corrosion, cathodic protection, atmospheric corrosion, underground corrosion.
The IMR capabilities related to corrosion are in the fields of metallurgy, inorganic solids, polymers, analytical chemistry, and reactor studies.
In metallurgy it has an outstanding, well-rounded research program.
In inorganic solids, high-temperature chemistry and ceramic coatings are of particular interest.
In polymers it has a competence in protective coatings and corrosion inhibitors.
In analytical chemistry there is an outstanding capability for the identification of corrosion products.
The reactor offers a new research tool and a new environment. A variety of coupling mechanisms are visualized as playing a vital role in success of the proposed Center. For instance, there would be a Federal scientists program in which scientists from other Government laboratories could do cooperative research at IMR. The Center would sponsor training in new measurement techniques and give short-term courses and workshops for non-NBS scientists and engineers. Industrial research associates, similar to those in many other areas of work in the NBS, would make possible cooperative corrosion research with industry. A visiting scientist program, similar to the present NAS-NRC postdoctoral program, would bring corrosion problems into contact with academic work. Other agency sponsorship of corrosion research would be encouraged at IMR. And, finally, NBS would undertake to sponsor contract research in the corrosion field in selected laboratories where exceptional and relevant competence was found.
The program of work in the Corrosion Center is visualized as one-half to two-thirds in the applied area and onethird to one-half in the fundamental area. Possible subjects for fundamental research might be: Film nucleation and growth, electrochemical corrosion, passivity, liquid metal attack, stress corrosion, and adhesion. Some possibilities in the applied area are: Saline water corrosion, biomedical systems, radiation conditions, protective coatings, and underground corrosion.
The distribution of personnel in the Center by about 1971 is visualized as follows: Directors' offices, 12; data and information centers, 20; scientists and engineers, 75; technical support, 78. This amounts to approximately 185 people. A total annual effort of about $4 million is visualized, with the Bureau supplying the space and about half of the operating funds.
In the discussion that followed the formal proposal, it was brought out that a significant feature of the envisioned Corrosion Center is its housing under one roof the basic scientists trying to develop the science underlying complex corrosion
phenomena and the engineers with specific corrosion problems
TITANIUM AND RUTILE As part of a broad program to stimulate titanium production, the Director of the Office of Emergency Planning, on January 24, 1967, announced an expansion goal providing for an increase in U.S. rutile production from 5,000 short tons annually to 75,000 short tons per year. In making the announcement he stated that in 1966 the United States imported 170,000 short tons and that 99 percent of this amount came from Australia. He further stated that rutile ore and concentrates are used to produce titanium metal, pigments, and welding rod coatings, and that titanium metal is being used extensively in ultra-highspeed aircraft. The Director of the Office of Emergency Planning indicated that the Department of the Interior had been requested to encourage the exploration, development, and mining of stockpile grade rutile ores and concentrates and to recommend programs for financing under the Defense Production Act borrowing fund. It was further stated in the announcement that the Department of the Interior may request funds for research in the beneficiation, upgrading, and utilization of low-grade domestic ores for the production of titanium metal. It was also announced that the Office of Emergency Planning had authorized the General Services Administration to develop a Defense Production Act domestic purchase program for stockpile grade rutile ore and concentrates.
The gross transactions for titanium under authority of the Defense Production Act have amounted to $229,945,000, and of this amount $217,066,000 was delivered to the Government. The inventories of titanium sponge as of June 30, 1967, amounted to 30,070 short tons. Of this total, 21,049 tons was in the Defense Production Act inventory and 9,021 tons was in the supplemental stockpile. The acquisition cost was $197,498,100 and the market value was estimated to be $72,014,700. The stockpile objective for titanium amounts to 37,500 tons.
The Bureau of Mines reports that consumption of titanium sponge metal increased markedly during the second quarter of 1967, but conversion of ingot into mill products declined slightly. The consumption of titanium sponge metal amounted to 5,746 short tons in the second quarter of 1967 in comparison with 5,190 short tons in the first quarter. The consumption of titanium sponge metal was 19,677 short tons in the calendar year 1966, and increased to 21,244 short tons for the year ending June 30, 1967.
The total inventory of rutile as of June 30, 1967, amounted to 47,617 tons. Of this total 17,385 tons was in the Defense Production Act inventory, 18,601 tons in the national stockpile, and 11,631 tons in the supplemental stockpile.
Domestic consumption of rutile concentrates reached a record 160,000 tons in 1966, an increase of 43,000 tons above 1965 and double the 1964 consumption. The consumption of concentrate was 53,400 tons in 1957 when the titanium industry reached the peak of its initial expansion period. Imports of rutile concentrate have continued to increase, most of which are consumed by the domestic sponge metal and pigment industries. A record 170,000 tons were imported in 1966. This compares with imports of 151,748 tons in 1965 and 110,981 tons in 1964.
Figures on the domestic production of rutile concentrate for 1966 and 1965 were withheld as confidential by the single U.S. producer. Output in 1964 was 8,062 tons. On May 3, 1967, the Department of Agriculture invited U.S. firms to submit barter offers for 3,400 tons of rutile produced in friendly foreign countries in exchange for Commodity Credit Corporation owned agricultural commodities for export. Rutile acquired under this barter program will be placed in the supplemental stockpile to be credited against the deficit in the national stockpile.
The probable ultimate net cost of the Defense Production Act expansion program of the 1950's for titanium is estimated to be $144,710,000. These transactions plus substantial assistance from the Department of Defense helped to create an entirely new metal industry within a few years. Most of the estimated loss under the borrowing authority transactions resulted from the declining price of titanium purchased by the Government. Losses already realized amount to $23,543,000 and estimated future losses amount to $121,167,000. The titanium program involved 19 borrowing authority transactions with private firms and Government agencies, and included facility expansions, commitments to purchase, and research and development.
TITANIUM AND THE SST
The Federal Aviation Administration states that materials for the supersonic transport have been a subject of speculation and study for well over a decade, but selection of the optimum structural material could not rationally be made until a reasonable estimate of the airplane characteristics (speed, size, and lifetime) were known. It is reported that these were reasonably established by 1960, at which time a joint industry-Government committee of materials specialists was formed, and under the direction of that committee, a complete program of testing and material selection was undertaken. This review, reported to have been conducted by the best authorities in the country, concluded that only three primary structural materials could be considered. These materials were (a) titanium, (6) stainless steel, or (c) superalloys. Other likely materials considered were found to be severely lacking in basic structural characteristics.
Aluminum alloys were considered to compare favorably with stainless steel at room temperature, but drop to approximately half the strength-to-weight ratio of stainless steel at 450° F., which corresponds to the speed of 2.7 times the speed of sound. It was estimated that designing the airframe of the Boeing B-2707 in the best available stainless steel alloy would reduce the SST payload by at least one-third as compared to titanium. The superalloys were found economical only for hotter locations, such as in the vicinity of the engines, and were