Sample records for steel-din-1-4970

  1. The irradiation behaviour of the austenitic stainless steel DIN 1.4970

    International Nuclear Information System (INIS)

    Huebner, R.


    The irradiation behaviour of the austenitic stainless steel DIN 1.4970 (15% Cr, 15% Ni, 1,6% Mn, 1,5% Mo, 0,4 - 1% Si, 0,3 - 0,5% Ti) has been examined in the irradiation experiment PFR-M2. The samples have been irradiated as pressurised capsules in the prototype fast reactor at Dounreay, Scotland, at 420, 500 and 600 C with maximum doses of 106, 81 and 62 dpa NRT . The stress-free and the stress-induced swelling and the irradiation induced creep could be determined by the diameter and length measurements. After the irradiation the density and the mechanical properties have been determined. Additionally the microstructure was investigated with a transmission electron microscope (TEM). All four lots show the maximum amount of stress-free swelling at 420 C. At 600 C no swelling can be detected up to the maximum dose of 62 dpa NRT . The lot with the lowest Si-content exhibits the highest amount of swelling at 420 C as well as at 500 C. Increasing the Si-content from 0.4% to 1% increases at 420 C the incubation dose from 20 to 40 dpa NRT , but has no influence on the swelling rate. Increasing not only the Si-content but also reducing the Ti-content from 0.5 to 0.3% increases not only the incubation dose but also reduces the swelling rate. At 500 C both the increase of the Si-content and the reduction of the Ti-content result in a reduced swelling rate without any effect on the incubation dose. Therefore the best swelling resistance is achieved with a high Si-content and a low Ti-content, resulting in an understabilised condition. The TEM analysis of the microstructure reveals the mechanisms by which the minor elements influence swelling. Increasing the Si-content increases the vacancy mobility and reduces therefore the void nucleation rate. This yields the increased incubation dose. But this mechanism is only working if the silicon is dissolved in the matrix. Swelling starts when the amount of dissolved silicon is reduced under a certain amount. The lots with a high Si

  2. Effect of heat treatment, with and without mechanical work, on the tensile and creep behaviour at 6000C of austenitic stainless steel stabilised with titanium

    International Nuclear Information System (INIS)

    Padilha, A.F.


    The effect of various heat treatments, with and without mechanical work, on the microstructure and the tensile and creep behaviour at 600 0 C of the titanium stabilised austenitic stainless steel DIN 1.4970, as well as the effects of aging temperature, pre-strain and small boron additions on the creep behaviour of these steels are discussed. The most probable mechanism is suggested. (Author) [pt

  3. Sodium corrosion tests in the ML 1 circuit

    International Nuclear Information System (INIS)

    Borgstedt, H.U.


    In the ML-1 circuit of the 'Juan Vigon' research centre in Madrid, sodium corrosion tests are being carried out on the austenitic steels DIN 1.4970 (X10NiCrMoTiB1515) and DIN 1.4301 (X5CrNi189) at temperatures between 500 and 700 0 C. The exposure time of the samples amounts to 6,000 h by now. Every 1,000 h, the samples were weighed in order to measure corrosion and deposition effects. After 3,000 and 6,000 h, some selected samples were destroyed for inspection. The results are given. (GSC) [de