INITIAL EXAMINATIONS OF THE WELDABILITY, CREEP PROPERTIES, TEMPERING RESPONSE AND GRAIN SIZE CONTROL IN LOW-ACTIVATION MARTENSITIC STAINLESS STEELS
Earlier work has identified low-activation martensitic stainless steel compositions having properties comparable to those of commercial 12%CrMoVNb steel. The welding characteristics, creep properties, additional mechanical properties and grain refinement techniques have been examined for these steels. Welding trials show that the LA7 alloy (11Cr-3W-O.2V) can be welded using TIG methods with preheat and post-weld stress relief heat treatment. Creep tests, which are still in progress, so far indicate that the steels LA7 and LA13 (9Cr-3W-0.25V) have higher creep strain rates and possibly lower rupture strengths than FV448 steel. An evaluation of the mechanical properties of some lower alloy content low-activation steels indicated that, as expected, the steels possessed lower strength coupled with an enhanced toughness. It has been demonstrated that grain refinement can be accomplished by means of tantalum additions, though the quantitative basis for the effect of grain refining additions remains to be established. There are strong indications that the soluble nitrogen content, possibly interacting with the manganese present, influences the delta ferrite content.
Bibliographic Reference: WRITE TO HER MAJESTY'S STATIONERY OFFICE, P.O. BOX 276, LONDON, SE1 9NH, MENTIONING REPORT CLM-R273, 1987, PRICE: UKL5.00
Record Number: 1989126055100 / Last updated on: 1989-03-01
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