Mechanism of Damping Capacity of High-Chromium Steels and a-Fe and Its Dependence on Some External Factors In Memoriam of Professor Vladimir J. Sarrak IGOR S. GOLOVIN The influence of heat treatment on the elastic and nonelastic parameters of internal friction of high-chromium ferritic alloys and a-Fe has been examined. Mechanisms of the formation of magnetoelastic and dislocation hysteresis have been investigated. Temperature ranges and tem- perature and amplitude critical points connected with different damping mechanisms have been established. Heat treatment for maximum damping capacity has been suggested, and the results of damping capacity of about 50 steels were generalized. I. INTRODUCTION HIGH-chromium steels are of great interest due to favorable mechanical, corrosion, and damping proper- ties. m High-chromium steel alloys are widely used in different branches of industry. In this respect, a high level and stability of the mechanical properties and damping capacity are necessary for their commercial use in wide temperature and amplitude ranges. The favorable position of high-chromium steels as high damping metals (hidamets) among other steels, metals, and alloys is shown in Scheme 1, which com- bines the information of the intrinsic damping capacity (~ = AW(A)/W(A) = 2rrQ ], AW(A) is dissipated, W(A) is stored energy, A is amplitude of deformation, and Q-~ is internal friction) of a lot of materials with very different levels of damping capacity and the main mechanism of damping. I21 The production of steels with a given combination of physical-mechanical properties and the increasing of sta- bility of these properties are interesting scientific and commercial tasks. The urgent problem is the investiga- tion of the influence of chemical composition, different heat-treatment regimes, degree of preliminary deforma- tion, aging temperature, temperature of measurements, etc. on the properties of high-chromium steels. The ma- terial a-Fe was chosen as a good model material with a body-centered cubic (bcc) lattice. The influence of the aforementioned parameters on mechanisms and the level of internal friction (IF) and shear modulus defect (DM) in high-chromium ferritic alloy are investigated in the present work. II. EXPERIMENTAL PROCEDURE The a-iron and bcc alloys with Cr content from 11 to 25 wt pct were used in the present work. The main heat- treatment regimes investigated here were the annealings IGOR S. GOLOVIN, Senior Researcher, formerly with the Physics of Metals Department, Central Research Institute of Iron and Steel Industry, Moscow 107005, Russia, is with Moscow State Aircraft Technology University, Petrovkast.27, Moscow 103767, Russia. Manuscript submitted August 4, 1992. of cold-worked samples in the temperature range from 100 ~ to 1200 ~ in some cases, additional low- temperature annealing (less than the Curie tem- perature) was used. Annealing in the range of "475 ~ embrittlement" was studied especially. The steels with 12 pct Cr were quenched from 1020 ~ to the martensite structure and annealed from 100 ~ to 850 ~ The chemical composition of the investigated Fe-Cr steels is shown in Table I. Some face-centered cubic (fcc) steels of Fe-(15 ... 24 pct) Ni-(12 to 18 pct) Cr, Fe(20 ... 35 pct) Mn-12 pct Cr systems and bcc steels of Fe-(3... 6 pct) Mo and Fe-Cr-V systems were used additionally (Table V). Scheme 1. Intrinsic Damping Capacity of Some Metals and Alloys mmpingl 1[}tEIIMW~ EC~IAMISMOFDAI~ING index I Movable Movable Reversable V0.I,%| domaln wails dislocatlon~ martenslte Heterogenity tO. 1, In structure [ e-Cr-A1 ]{ + Fe-Cr-Y // ]} - Ti-Bi alloy + Fe-Cr-Mo // /}-- TI-Pb,Sn ~Fe-Cr,Fe-Wl/ ll-" Alloys of "l'Fe-V.Fe-Mol/ t-- alloys -J| | system A1-Zn N~I;C~ .|~-- Grey cast 10 ='L iron -- Fe -. 11 I 1D T TC- 12%Or steel~ ', ]~--- Fe-eu I~ Graphite st.l I Jt-'~ Brass }i rO.08%C steeli |r--7 AI powder /V r Stainless I r 1 ] Tt-Bi |--J steel I I, ~" ~ .~_o~ A 2o Cast 3o M iron 15 G lo~ F~"L 0.4-o.gOsEeel ] _j-~ (og,gz) ~-Zr,i~-Mn -t-~-Sl alloy~ (KIXI, SIXI, MI-F,K1-F) M~-AI ,Zn,Mn go I 15, MPa ~( u-13AI-4NI CUALNISILI -}4n-Cu.NI-TI alloys (Sonoston, Incramute) ~- Fe-Mq-Cr 1 alloys ~-- Tl-al loys 75Mn25Cu ol/f-- lo[, 45TiSgN~ o 2 ~ - ~ - 5, MPa LOW DAIdPING Most of the medlum-cacbon, hlEh-carbon low alloyed commercial steels; Alloys on the base of A1 (AI-8%b~, 0,1-1,0 AI-IOZZn, AI-O,2%TI, AI-IOZSI. AI-SZCu). TI alloys, etc Io'~ T 10-3 71 dO-' u D ]..c'T Elinvar (36Nl,gcr,3W) ~ 45Nt,Cr,T1 s A l.~-~Durlnval(42N1,2T1.5Cr'+ldo,A1) |[ 46N1 ,Or,TI---~[ R M |_i-,TermeLast 4290 (40NI,OMo,_Be!~-t [ Y P J~.Termelast 5409 (37Ni,8Cr,ue) Lt 46NI,Cr,Mo.Ti,AI[ I Ill L'Sumltomo EL-3 (42N1.rCr,3T1)]T~/ 44NI,Cr,lWo,TI ~ [ i N l/ tTokln TE-2, Tokln TE-3 ~ l 0 GLOW] L Nl-Span C (42N1.SCr,3TI,Al,I~)J 1 ! W 10 -4 LIO "4 L Longitudinal Oscillation. Shear osc. Lonff. osc. METALLURGICAL AND MATERIALS TRANSACTIONS A VOLUME 25A, JANUARY 1994-- I 11