Current state of Fe-Mn-Al-C low density steels

https://www.tandfonline.com/doi/pdf/10.1088/1468-6996/14/1/014205

Fe–Al–Mn–C lightweight structural alloys: a review on the microstructures and mechanical properties

During the last years, the scientific and industrial community has focused on the astonishing properties of Fe-Mn-Al-C steels. These high advanced steels allow high-density reductions about ~15% lighter than conventional steels, high corrosion resistance, high strength (ultimate tensile strength (UTS) ~1 Gpa) and at the same time ductilities above 60%. The increase of the tensile or yield strength and the ductility at the same time is almost a special feature of this kind of new steels, which makes them so interesting for many applications such as in the automotive, armor and mining industry. The control of these properties depends on a complex relationship between the chemical composition of the steel, the test temperature, the external loads and the processing parameters of the steel. This review has been conceived to tried to elucidate these complex relations and gather the most important aspects of Fe-Mn-Al-C steels developed so far.

A General Perspective of Fe-Mn-Al-C Steels

During the last years, the scientific and industrial community has focused on the astonishing properties of Fe–Mn–Al–C steels. These high advanced steels allow high-density reductions about ~ 18% lighter than conventional steels, high corrosion resistance, high strength (ultimate tensile strength ~ 1 Gpa), and at the same time ductility above 60%. The increase in the tensile or yield strength and the ductility at the same time is almost a special feature of this kind of new steels, which makes them so interesting for many applications such as in the automotive, armor, and mining industry. The control of these properties depends on a complex relationship between the chemical composition of the steel, the test temperature, the external loads, and the processing parameters of the steel. This review has been conceived to elucidate these complex relations and gather the most important aspects of Fe–Mn–Al–C steels developed so far.

A general perspective of Fe–Mn–Al–C steels

http://liu.diva-portal.org/smash/get/diva2:438363/FULLTEXT01

Influence of high temperature hold times on the fatigue crack propagation in Inconel 718

Creep crack growth behavior at 1033K of directionally solidified CM 247 LC — a cast nickel-base superalloy

Fatigue and fracture behavior of a nickel−chromium free austenitic steel

Creep-rupture properties of a columnar-grained nickel-base superalloy have been evaluated over a wide temperature range (1033 to 1311 K) and stress levels (80 to 850 MPa). Creep data analyses based on the conventional approach as well as on a new graphical method—the Β-envelope method (Ref 1)—have been carried out for creep strain and life estimation purposes. The relation between minimum creep rate of the alloy with the applied stress obeys simple power law, whereas the rupture data of the alloy fits well to the Larson-Miller parameter. Also, the Monkman-Grant relation between the minimum creep rate and the rupture life produces a trend with some degree of scatter in the data. The latter relation in its generalized form by the Β-envelope method exhibited the best correlation with significantly reduced scatter in the data.

Creep data analyses of a columnar-grained nickel-base superalloy by conventional and β-envelope methods

The conventional stainless steels are used extensively as important structural materials for cryogenic as well as for high-temperature applications. They contain chromium and nickel as their major alloying elements. These two alloying elements are thought to be of strategic importance. Thus, there has been considerable effort all over the world to replace alloys based on Fe-Cr-Ni-C system by the relatively inexpensive Fe-Al-Mn-C system. In a program focused towards this objective, a solid-solution strengthened austenitic steel of the Fe-Al-Mn-C system has been developed in the laboratory. A particularly interesting observation in austenitic alloys of the Fe-Mn-Al-C system is the high work-hardening rate as a result of strain-induced phase transformation or by the formation of deformation twinning. These deformation mechanisms depend mainly on the amounts of carbon and aluminum present in the alloys. In the present alloy, with 0.45%C and 2.8%Al, a high work-hardening rate has been observed at room temperature. The deformation studies showed a high dislocation density as the cause for the high work-hardening rate in the steel. The observed deformation behavior of the steel has been explained on the basis of results available on similar alloy systems from the literature and is presented in this paper.

M.S.Gopala Krishna

Papers

Creep crack growth behavior at 1033K of directionally solidified CM 247 LC — a cast nickel-base superalloy

Fatigue and fracture behavior of a nickel−chromium free austenitic steel

Creep data analyses of a columnar-grained nickel-base superalloy by conventional and β-envelope methods

Deformation behaviour of a nickel-chromium free austenitic steel

An experimental study on abrasive wear behaviour of WC-12Co and WC-20Cr₂C3-7Ni coatings