Paper No

MICROSTRUCTURAL MAPPING OF HADFIELD MANGANESE STEEL-3401 IN AGING TREATMENT 1

Reza Fadhila, 1A.G.Jaharah, 1C.H.Che Haron, 1M.Z.Omar, 1J. Syarif, 2A.Manaf and 1 C.H.Azhari 1

2

Department of Mechanical and Materials Engineering Faculty of Engineering Universiti Kebangsaan Malaysia 43600, Bandar Baru Bangi, Malaysia

Research Centre for Materials Science and Engineering Universitas Indonesia Jalan Salemba Raya No 4 Jakarta 1043,Indonesia ABSTRACT

Hadfield steel used for railroad tracks was investigated for microstructural changes due to an aging treatment regime. The steel was subjected to solution treatment by heating at a temperature of 1000ºC-1090ºC and then water quenched. The as-quenched material was then investigated for the development of microstructure in an aging treatment by heating at various temperatures (400ºC, 450ºC, 500ºC, 550ºC and 600ºC) and at two holding times (30min, 60min). The ensuing microstructure was then examined for morphology using scanning electron microscopy (SEM) and verified for elemental analysis using Xray diffractratometry (XRD) as well as X-ray fluorescence spectroscopy (XRF). Results of the morphological mapping showed that at lower temperatures, ferrites grow in the form of sheaves of parallel plates which nucleated at austenite grain surfaces. At a higher temperature, the ferrites gave way to acicular ferrite plates, growing in many different directions. A new phase was formed in the 400ºC to the 550ºC which was confirmed by differential thermal analysis (DTA) to be the transformation of lower bainite to the upper bainite. The upper threshold for upper bainite formation was at 600ºC when again the ferritic structure was observed. The XRD and XRF data showed that the phase transformation observed in the morphological mapping matched.

Introduction During the late of 1920s, in the course of these pioneering studies on the isothermal transformation of austenite at temperatures above that at which martensite first forms, but below that at which fine pearlite is found, Davenport and Bain (1930) discovered a new microstructure consisting of an ‘acicular, dark etching aggregate’ which was quite unlike the pearlite or martensite observed in the same steel. In 1934, the research staff of the laboratory named the microstructure ‘Bainite’ in honour of their colleague E. C. Bain who had inspired the studies, and presented him with the first ever photomicrograph of bainite, taken at a magnification of x 1000 (Smith, 1960; Bain, 1963) The name ‘bainite’ did not immediately catch on. It was used rather modestly even Bain and his co-workers. In a paper on the nomenclature of transformation products in steels, Vilella, Guellich and Bain (1936) mentioned an ‘unnamed, dark etching, acicular aggregate somewhat similar to martensite’ when referring to bainite. Hoyt, in his discussion to this paper appealed to the authors to name the structure, since it had first been produced and observed in their laboratory. Davenport (1939) ambiguously referred to the structure, sometimes calling it ‘a rapid etching acicular structure’, at other times calling it bainite. In 1940, Greninger and Troiano used the term ‘Austempering Structures’ instead of bainite. The 1942 edition of the book The Structure of Steel (and its reprinted version of 1947) by Gregory and Simmons contains no mention of bainite. The high-range and low-range variants of bainite were later called ‘upper bainite’ and ‘lower bainite’ respectively (Mehl, 1939) and this terminology remains useful to this day. Smith and Mehl (1942) coined the term ‘feathery bainite’ for upper bainite which forms largely, if not exclusively, at the austenite grain boundaries in the form of bundles of plates, and only at high reaction temperatures, but this description has not found frequent use. Both upper and lower bainite were found to consist of aggregates of parallel plates, aggregates which were later designated sheaves of bainite (Aaronson and Wells, 1956). Early work into the nature of bainite continued to emphasize its similarity with martensite. Bainite was believed to form with a super saturation of carbon (Wever, 1932; Wever and Jellinghaus, 1932; Portevin and Jolivet, 1937, 1938; Portevin and Chevenard, 1937). It had been postulated that the transformation involves the abrupt formation of flat plates of supersaturated ferrite along certain crystallographic planes of the austenite grain (Vilella et al., 1936). The ferrite was then supposed to decarburize by rejecting carbon at a rate depending on temperature, leading to the formation of carbide particles which were quite unlike the lamellar cementite phase associated with pearlite. The transformation was believed to be in essence martensitic, ‘even though the temperature be such as to limit the actual life of the quasi-martensite to millionths of a second’. Bain (1939) reiterated this view in his book The Alloying Elements in Steel. Isothermal transformation studies were by then becoming very popular and led to a steady accumulation of data on the bainite reaction, still variously referred to as the ‘intermediate transformation’ ‘dark etching acicular constituent’, ‘acicular ferrite’, etc. In many respects, isothermal transformation experiments led to the clarification of microstructures, since individual phases could be studied in isolation. There was, however, room for difficulties even after the technique became well established. For

alloys of appropriate composition, the upper ranges of bainite formation were found to overlap with those of pearlite, preceded in some cases by the growth of proeutectoid ferrite. The nomenclatures thus became confused since the ferrite which formed first was variously describes as massive ferrite, grain boundary ferrite, acicular ferrite, Widmannstätten ferrite, etc. On a later view, some of these micro constituents are formed by a ‘displacive’ or ‘military’ transfer of the iron and substitutional solute atoms from austenite to ferrite, and are thus similar to carbon-free bainitic ferrite, whereas others form by a ‘reconstructive’ or ‘civilian’ transformation which is a quite different kinetic process (Buerger, 1951; Christian, 1965a). High–carbon steels can sometimes transform to plates of lower bainite which do not have a homogeneous microstructure (Okamoto and Oka, 1986). When observed using light microscopy, a microscopic plate of lower bainite is seen to have a black line running centrally along its axis. The lower bainite is actually found to evolve in two stages, from thin-plate martensite which forms first by the isothermal transformation of austenite, and which then stimulates the growth of the adjacent bainite regions. Okomoto and Oka deduced that at relatively high transformation temperatures, the steels react to give lower bainite, but as the transformation temperature is reduced to below a certain temperature Tr, this is replaced by the lower bainite with a thin-plate martensite, which then gives way to just the thin-plate martensite; at a sufficiently low temperature (below the conventional Ms temperature), ordinary martensite with a lenticular plate morphology forms by the athermal transformation of austenite. It was noted above that both the lower bainite isothermally form in the temperature range Tr → Ms. Okamoto and Oka demonstrated that the difference between these two temperatures diminishes as the carbon concentration of the steel decreases, until at about 1 wt% C, it becomes zero. Consequently, neither of these phases has been reported to occur in lower carbon steels. The terminology thin-plate martensite has its origins in work done on nickel rich Fe-Ni-C alloys, where the martensite transformation temperatures are well below - 100°C (Maki et al.; 1973, 1975). The martensite then tends form as extremely thin, parallel-sided plates in preference to much thicker lenticular plates, especially as the carbon concentration is increased. Because of their large aspect ratios, the thin plates are elastically accommodated in the austenite matrix; their interfaces remain glissile. The plates can therefore thicken as the temperature is reduced, or indeed become thinner as the temperature is raised. As summary that, bainite grows in the form of clusters of thin lenticular plates or laths, known as sheaves. The plates within a sheaf are known as sub-units. The growth of each sub-unit is accompanied by an invariant-plane strain shape change with a large shear component. The sub-units are to some extent separated from each other by films of residual phases such as austenite or cementite, so that the shape strain of the sheaf as a whole tends to be much smaller than that of an isolated sub-unit. The plates within any given sheaf tend to adopt almost the same crystallographic orientation and have identical shape deformations. Because of the relatively high temperatures at which bainite grows (where the yield stresses of ferrite and austenite are reduced), the shape strain causes plastic deformation which in turn leads to relatively large dislocation density in both the parent and product phases; other kinds of defects, such as twinning and faulting are also

found in the residual austenite. This plastic accommodation of the shape change explains why each sub-unit grows to a limited size which may be far less than the austenite grain size. The dislocation debris stifles the motion of the otherwise glissile interface. Consequently, the sheaf as a whole grows by the repeated ‘nucleation’ of new sub-units, mostly near the tips of those already existing. The bainitic / austenite orientation relationship is always found to lie well within the Bain region; this and other features of the transformation are broadly consistent with the phenomenological theory of martensite crystallography. The growth of bainitic ferrite undoubtedly occurs without any redistribution of iron or substitutional solute atoms, even on the finest conceivable scale at the transformation interface. Although some excess carbon is retained in solution in the bainitic ferrite after transformation, most of it is partitioned into the residual austenite, and in the case of lower bainite, also precipitated as carbides within the ferrite. All of the observed characteristics of bainitic ferrite prove that it grows by a displacive transformation mechanism.

2. Materials and Methods 2.1 Experimental details The sample of the Hadfield’s manganese steel used was Krupp 3401 with the chemical composition as shown in Table 1. Table 1 Composition in Wt % Composition Standard a Modified b Modified c % C % Mn % Si % Ni % Cr a. b. c.

1.0-1.2 11-14 -

1.059 11.34 0.3694 0.1345 0.1362

(Zr)

11.36 0.6252 0.0599 0.1668

Standard Hadfield’s steel as theoretical Actual analysis composition by Spectrometer (PT KIM) Actual analysis composition by XRF

The chemical composition was examined in PT Growth Sumatra, KIM, North Sumatra – Indonesia, using the spectrometer. Validation composition data’s was examined in University of Indonesia, using the XRF. Test specimens of 10 x 20 x 25 mm were prepared for metallographic inspection. They were cut from plates, by precision cutting machine in order to avoid phase transformation changes. Samples were heat-treated at 1050ºC for 1 hour in a PID electric furnace (Vectar VHT-3), then quenched in water to homogenize the sample as an austenite phase. As a second treatment, sample was reheat-treated at different temperatures for various holding times. The Aging temperatures were set between 400ºC to 600ºC at 50ºC interval.

Table 2. Showing the heat regimes for the samples. Temperature No. Homogenize 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.

1050ºC 1050ºC 1050ºC 1050ºC 1050ºC 1050ºC 1050ºC 1050ºC 1050ºC 1050ºC

Holding Temperature Holding reheating time time (minutes) (minutes) 60 400ºC 30 60 400ºC 60 60 450ºC 30 60 450ºC 60 60 500ºC 30 60 500ºC 60 60 550ºC 30 60 550ºC 60 60 600ºC 30 60 600ºC 60

After heating at two varying times (30 and 60 minutes), the sample was cooling in the air. The sample was ground and polished using an automatic polishing unit. Grinding was performed using silicon carbide abrasive paper of grit P 100, P 350, P 600, P 800, P 1000, P 1500 and P 2000 respectively. Finally, the sample was polished using an alumina paste 1µ to obtain a mirror like surface, and then the sample was cleaned by using the ultrasonic cleaning machine, Branson 1210, Model B1210E-MT 47 KHz, 230 Volt. An etched using the enchant as shown in Table 3. Table 3. Etchant composition for Mn-steel Type solution Composition Solution A 100 ml alcohol 3 ml HNO3 Solution B 90 ml ethanol 10 ml HCl Solution C 100 ml ethanol 2 ml NH4OH The samples were etched in the order of solution A, B, C followed by rising after each solution etching. The microstructure was characterized using an optical image analyzer microscope (Epiplan HDlenz, Carl Zeiss, 220 V- 60Hz, 80 VA) at a magnification of 200X. For the characteristic of the treatment, the sample is examined using XRDiffractometer (Philips PW/1835 NC9430 entirely with computer temperature interface) and Differentials Thermal Analyzer (DTA-50 Shimadzu C300530000176, 220 Volt BLW-50)

3.0 Results and Discussion Earlier work [

E.E. Frank, Evolution of the rail-bound manganese frog, Transport. Res. Rec. 1071 (1986) 43-44. - P. Rama Rao, V.V. Kutumbarao, Developments in austenitic steels containing manganese, Int. Metall. Rev. 34 (2) (1989) 69. - D.M. Rodionov, M.G. Lyubinov, Y.E. Mishutin, A. Stepanova, L.V. Smirnov, Segregation of impurities on the free surface of Hadfield Steel during heating, Phys. Met. Metall. 68 (5) (1989) 73-78. - N.N. Stepanova, D.P. Rodionov, M.G. Lyubimov, S..V. Nesgovorov, V.K. Farafonov, L.B. Smirnov, Grain boundary embrittlement of Hadfield steel, Phys. Met. Metall. 68 (4) (1989) 179-183. - R.W Smith, Development of high manganese steel for heavy duty cast-

to-shape application, Journal of Materials Processing Technology 153-154 (2004) 589-595. ] has also reported that the Hadfield’s manganese steel with a composition of Fe-1.2%C and 13%Mn, normally has a structure of metastable austenite phase which is obtained by water-quenching the steel from annealing temperature of 1050ºC. The original manufactures of the steel called this treatment “water toughening’. It results in the solid solution of carbides causing brittleness and the production of almost pure austenite. The austenite grain boundaries are well defined and of approximately uniform thickness. If water toughened manganese steel is aging, partial decomposition of the austenite occurs. The extent of this decomposition depends on the time and temperature of the tempering treatment. In many respects, isothermal transformation experiments led to the clarification of microstructures, since individual phases could be studied in isolation. There was, however, room for difficulties even after the technique became well established. For alloys of appropriate composition, the upper ranges of bainite formation were found to overlap with those of pearlite, preceded in some cases by the growth of proeutectoid ferrite. The nomenclatures thus became confused since the ferrite which formed first was variously describes as massive ferrite, grain boundary ferrite, acicular ferrite, Widmannstätten ferrite, etc. On a later view, some of these micro constituents are formed by a ‘displacive’ or ‘military’ transfer of the iron and substitutional solute atoms from austenite to ferrite, and are thus similar to carbon-free bainitic ferrite, whereas others form by a ‘reconstructive’ or ‘civilian’ transformation which is a quite different kinetic process (Buerger, 1951; Christian, 1965a).

3.1.1 Development of microstructure at heating regimes of 1050ºC following by water quenching

The microstructure of Hadfield’s austenitic manganese steel when heat treated to 1050ºC then followed by rapid cooling process is shown in Fig. 1. Fig. 1 shows austenite grains of Hadfield’s steel with twins as similarly found by previous researchers [ S.B. Sant, R.W. Smith, The mechanism of work hardening in austenitic Fe-Mn-C and Fe-Mn-C-V alloys, in: Proceedings of the Conference on Strength of Metals and Alloys, vol. 1, Pergamon Press, Montreal, Canada, 1985, pp. 219-224 and S.B. Sant, R.W. Smith, A study of work-hardening behaviour of austenitic manganese steels, J. Mater. Sci. 22 (1987) 1808-1814. ]

Fig.1 Sample No.1 - 1050ºC for 1 hour - water quenching

3.1.2. Development of microstructure at reheating regimes of 400ºC

Figure. 2a and 2b show the microstructure of Hadfield’s austenitic manganese steel after heating to 1050ºC then subsequently reheated at in 400ºC at various holding times followed by air cooling condition.

Fig.2a Sample No.1 - 1050ºC for 1 hour - water quenching subsequently reheated 4000C -30 minutes aircooling

Fig.2b Sample No.1 - 1050ºC for 1 hour - water quenching subsequently reheated 4000C -60 minutes aircooling

Fig.2a and 2b shows initially forming of bainite structure which still get involved in the austenite structure. The primarily appearance of bainite structure in austenite structure wherein figure 2b seem excessively than in figure 2a.

3.1.3 Development of microstructure at tempering regimes of 450ºC

Figures 3a and figure 3b are showing the microstructure of Hadfield’s austenitic manganese steel after the treatment of 1050ºC subsequent reheating to 450ºC at two various holding time followed by air cooling process.

Fig.3a Sample reheat in 450ºC for 30 minutes

Fig.3b Sample reheat in 450ºC for 60 minutes

Fig.3c Sample 450ºC - 30 minutes M500x

Fig.3d Sample 450ºC - 60 minutes M500x

In Figures 3a and figure 3b, the ferrite which formed first was variously describes as massive ferrite (in fig 3a) and grain boundary ferrite ( in fig 3b). On a later view, some of these micro constituents are formed by a ‘displacive’ or ‘military’ transfer of the carbon and substitutional solute atoms from free bainite to ferrite transformation. In a large Optical magnification, the microstructure of these regimes showed as figure 3c and figure 3d. 3.1.4 Development of microstructure at tempering regimes of 500ºC

Fig.4a Sample reheat 500ºC for 30 minutes

Fig.4b Sample reheat 500ºC for 60 minutes

Figure 4a and 4b shows the microstructure of Hadfield’s austenitic manganese steel after treatment 1050ºC then subsequent reheating to 500ºC at two various holding times then cooling in the air . Comparing reheated in temperature 450ºC aging 60 minutes with temperature 500ºC with the interval time aging of 30 and 60 minutes, temperature increases, the possibility the ferrite which formed in grain boundary is excessively for temperature 500ºC. In temperature aging of 500ºC air-cooling process, ferrite which form in grain boundary seem grown to attempt in its boundary. In a large Optical magnification, the microstructure of these regimes showed as figure 4c and figure 4d.

Fig.4c Sample reheat 500ºC for 30 minutes M500x

Fig.4d Reheat 500ºC for 60 minutes M500x

Some of these micro constituents are formed by a ‘displacive’ or ‘military’ transfer of the iron and substitutional solute atoms from austenite to ferrite, and are thus similar to carbon-free bainitic ferrite, whereas others form by a ‘reconstructive’ or ‘civilian’ transformation

3.1.5 Development of microstructure at tempering regimes of 550ºC

Usually, a fully austenitic structure, essentially free of carbides and reasonably homogeneous with respect to carbon and manganese, although this is not always attainable in heavy sections or in steels containing carbide-forming elements such as chromium, molybdenum, vanadium and titanium [ T.H. Middleham, some alloy additions to manganese steel, Alloys Met. Rev. 12 (112) (1964) 11. - V.I. Grigorkin, G.V. Korotushenko, Effect of carbon, manganese plastic deformation and heat treatment on the structure and properties of austenitic manganese steel, Met. Sci. Heat Treatment Met. 2 (1968) 130-132. - V.I. Grikorkin, I.V. Frantsenyuk, I.P. Galkin, A.A. Osetrov, A.T. Chemeris, M.F. Cheminilov, Increase in the wear resist of

Figure 5a and figure 5b show the microstructure of Hadfield’s austenitic manganese steel after treatment 1050ºC subsequent reheat in 550ºC in air cooling process. By increasing the tempering temperature, more precipitates were formed in the grain boundary the microstructure showing that more precipitate will form in grain boundary but ferrite which form in grain boundary seem still attempt in its boundary. hammer mill hammers, Met. Sci. Heat Treatment Met. 16 (4) (1974) 52-354. ].

Fig.5a Sample reheat 550ºC for 30 minutes

Fig 5b Sample reheat 550ºC for 60 minutes

On the other hand, in large magnification (figure 5c and 5d), it seem that at the same rate of cooling, the ability of dispersed precipitated in grain after cooling is subordinate depending to temperature treatment, and precipitation in grain boundary formed a new phase [ Krauss, G. 1980. Steels: Principles of Heat Treating of Steels. Metals Park, Ohio: ASM International. - Ashby, M.F., and Easterling, K.E. 1982. A first report on diagrams for grain growth in welds. Acta Metall.30:1969. ]. The aging experiments demonstrate the kinetics of the decomposition of a new phase into a microstructure. This phenomenon predicted

according the concept of diffusion and transformation [15-17]. It is predicted that a new phase is form although the ferrite needle still present in the boundary .

Fig 5c Sample reheat 550ºC- 30 minutes M500x

Fig 5d Sample reheat 550ºC- 60 minutes M500x

3.1.6 Development of microstructure at tempering regimes of 600ºC

Fig.6a Sample reheat 600ºC for 30 minutes

Fig.6b Sample reheat 600ºC for 60 minutes

Figure 6a and 6b show the microstructure of Hadfield’s austenitic manganese steel after treatment 1050ºC subsequent reheat in 600ºC for a vary of time then air cooling. The microstructures in these figures described the phenomena of diffusion happening more obviously. Large microstructure magnification is showing in figure 6c and 6d bellows.

Fig.6c Reheat 600ºC for 30 minutes M500x

Fig.6d Reheat 600ºC for 60 minutes M 500x

3. Conclusion

This paper presents the microstructural development of the austenitic manganese steel3401 due to different heating regimes followed by air cooling process. The material is heated to 1050ºC followed by a water quenching cooling process which caused the solid solution of the carbides to be precipitated in the grain of the pure austenite phase. By reheat this austenite phase, iso thermal phases of bainitic phase will occur. The time and temperature of reheating tempering will affect the isothermal phase forming. The Reheating temperature is set between 400ºC to 600ºC with an interval of 50ºC for two various holding time 30 and 60 minutes. The microstructure examination of the samples show that the formation of bainite begins by precipitation of iron and manganese carbides at the grain boundaries, then progressively followed by the appearance of a new constituent which later extend into its grain. When observed using light microscopy, a microscopic plate of lower bainite is seen to have a black line running centrally along its axis. The lower bainite is actually found to evolve in two stages, from thin-plate martensite which forms first by the isothermal transformation of austenite, and which then stimulates the growth of the adjacent bainite regions. The growth of bainitic ferrite undoubtedly occurs although some excess carbon is retained in solution in the bainitic ferrite after transformation, most of it is partitioned into the residual austenite, and in the case of lower bainite, also precipitated as carbides within the ferrite. All of the observed characteristics of bainitic ferrite prove that it grows by a displacive transformation mechanism. Development in microstructure mapping resulting from such studies should also enriching phenomena in the subject of applied physical metallurgy. The study helps to understand better about the kinetic aspects in phases and microstructure development for manganese steel alloys. Properties such as excellent toughness and good wear resistance are expected in produce in future. For the more the developed microstructure mapping presented will enrich the phenomena in applied physical metallurgy

References 1) D.M. Rodionov, M.G. Lyubinov, Y.E. Mishutin, A. Stepanova, L.V. Smirnov, Segregation of impurities on the free surface of Hadfield Steel during heating, Phys. Met. Metall. 68 (5) (1989) 73-78. 2) Micgalon D. Mazet.G and Burgio C. 1976. Manganese steel for abrasive environments. A conditioning steel process for Hadfield Manganese steel and a novel method of producing FAM bearings from the same material. Tribology International. Aug. 171-178. 3) E.H. Taylor, Internal Report Explosive Depth Hardening, C.P. Rail, 27 January 1987. 4) E.H. Taylor Memorandum TRCHWORK (9-2-26(35-201-CIGGT)0M))496), 9, 1986. 5) J. Mendez, M.Ghoreshy, Weldability of austenitic manganese steel, Journal of Materials Processing Technology 153-154 (2004) 596-602. 6) S.B. Sant, R.W. Smith, The mechanism of work hardening in austenitic Fe-Mn-C and Fe-Mn-C-V alloys, in: Proceedings of the Conference on Strength of Metals and Alloys, vol. 1, Pergamon Press, Montreal, Canada, 1985, pp. 219-224. 7) S.B. Sant, R.W. Smith, A study of work-hardening behaviour of austenitic manganese steels, J. Mater. Sci. 22 (1987) 1808-1814. 8) T.H. Middleham, some alloy additions to manganese steel, Alloys Met. Rev. 12 (112) (1964) 11. 9) V.I. Grigorkin, G.V. Korotushenko, Effect of carbon, manganese plastic deformation and heat treatment on the structure and properties of austenitic manganese steel, Met. Sci. Heat Treatment Met. 2 (1968) 130-132. 10) V.I. Grikorkin, I.V. Frantsenyuk, I.P. Galkin, A.A. Osetrov, A.T. Chemeris, M.F. Cheminilov, Increase in the wear resist of hammer mill hammers, Met. Sci. Heat Treatment Met. 16 (4) (1974) 52-354. 11) G.I. Sil’man, N.I. Prristuplyuk, M.S. Frol’tsov, effect of vanadium on the structure and properties of high-manganese steel, Met. Sci. Heat Treatment Met. 22 (2) (1980) 124-127. 12) Honeycomb, R.W.K, and Bhadeshia, H. K.D.H. 1982. Steels, Microstructure and Properties. Metal Park, Ohio : ASM International. 13) P. Rama Rao, V.V. Kutumbarao, Developments in austenitic steels containing manganese, Int. Metall. Rev. 34 (2) (1989) 69. 14) E.E. Frank, Evolution of the rail-bound manganese frog, Transport. Res. Rec. 1071 (1986) 43-44. 15) N.N. Stepanova, D.P. Rodionov, M.G. Lyubimov, S..V. Nesgovorov, V.K. Farafonov, L.B. Smirnov, Grain boundary embrittlement of Hadfield steel, Phys. Met. Metall. 68 (4) (1989) 179-183. 16) R.W Smith, Development of high manganese steel for heavy duty cast-to-shape application, Journal of Materials Processing Technology 153-154 (2004) 589-595. 17) A. Chojecki, 1. Telejko, Effect of the chemical composition of Fe-Mn-C-P alloys on the brittle-ductile transition temperature in the solidification range, Steel Res. 63 (10) (1992) 447-452. 18) Krauss, G. 1980. Steels: Principles of Heat Treating of Steels. Metals Park, Ohio: ASM International. 19) Ashby, M.F., and Easterling, K.E. 1982. A first report on diagrams for grain growth in welds. Acta Metall.30:1969.