American Society for Metals
DEFECTS IN EXTRUDED AND DRAWN MILL PRODUCTS
11-12 September 1974
Chatham Center, Pittsburgh
THE QUALITIES OF AUSTENITIC STAINLESS STEEL TUBES
FROM CONTINUOUSLY-CAST BLOOMS
Nippon Steel Corporation
Since the No.2 continuous casting machine was installed in 1968 for casting of blooms for austenitic stainless steel tubes, research and development efforts in the casting and extrusion techniques aiming at the improvement of the quality and product yield of austenitic stainless steel tubes have produced a number of substantial results. Thus, a method for stabilized manufacture of stainless steel tubes from continuously-cast blooms has been established. This report discusses workability, surface conditions of extruded tubes, inclusions and segregation, which are particularly important determinants of the quality of stainless steel tubes made from continuously-cast blooms.
conditions of extruded tube
On the strength of the improved quality of blooms and by employing the production process suited to continuously-cast blooms, product quality of continuously-cast blooms has now become stabilized and fully comparable to that of the conventional ingot-blooms.
Mr. Chairman, thank you for your kind introduction.
Ladies and gentlemen, my name is Motoya Fujii and Ifm engaged in the hot extrusion plant at Hikari works of Nippon Steel Corporation.
Today Ifm very honored to present a report titled gQualities of austenitic stainless steel tubes from continuously cast bloomsh.
Well, the austenitic stainless steel tubes are indispensable for the construction of chemical plants and power plants, and their demand has been steadily on the increase with the remarkable industrial progress of recent years.
In response to this demand, in 1968, Hikari Works installed a continuous bloom casting machine for the austenitic stainless steel tubes. Since then, many studies and technical development concerning casting and extrusion technology have been undertaken to improve the qualities and to increase the yields of austenitic stainless steel tubes.
Through these studies and technical developments, we have established a process for stable manufacturing of high-quality austenitic stainless steel tubes from continuously cast blooms.
And, I would like to explain the outline of my report with the aid of slides.
Slide 1 --
Slide 2 --
Now Ifd like to summarize my report. We have discussed the hot extrusion process of austenitic stainless steel tubes from continuously cast blooms and the quality of the blooms obtained. In producing austenitic stainless steel tubes from continuously cast blooms, it is essential to use sound continuously cast blooms and to develop rolling and heat-treatment processes that are adapted to continuously cast blooms if the qualities of the required product, especially tube surface conditions, inclusions. And homogeneity, are to be secured.
The use of continuously cast blooms for the production of stainless steel tubes has just began, and the scope of application will be more and more increasingly expanded through the refining of clean stainless steel by the AOD process and through the rapid improvement of continuously cast blooms by the special casting practice. We intend to continue tests on the continuous casting.
I hope my report will help you in someway with your business. And if you would like to know the minute details, please refer to the report at your hand.
Thank you very much for your kind attention