Influence of Manganese and Nickel on the α´ Martensite Transformation Temperatures of High Alloyed Cr‐Mn‐Ni Steels

Abstract

The martensite start temperature (Ms), the martensite austenite re‐transformation start temperature (As) and the re‐transformation finish temperature (Af) of six high alloyed Cr‐Mn‐Ni steels with varying Ni and Mn contents in the wrought and as‐cast state were studied. The aim of this investigation is the development of the relationships between the Ms, As, Af, T0 temperatures and the chemical composition of a new type of Cr‐Mn‐Ni steels. The investigations show that the Ms, As and Af temperatures decrease with increasing nickel and manganese contents. The Af temperature depends on the amount of martensite. Regression equations for the transformation temperatures are given. The experimental results are based on dilatometer tests and microstructure investigations.

Deformation Mechanisms in Austenitic TRIP/TWIP Steel as a Function of Temperature

“…Neighboring areas are enriched by Mn and Ni changing the deformation behavior locally, which in general depends on the chemical composition. As the influence of the individual chemical elements is discussed elsewhere by Jahn et al, [32] the segregation behavior is not the focus of the present paper.…”

“…A higher phase fraction of a¢-martensite could be found already at the beginning of the mechanical experiments, as the testing temperature was situated below the M s temperature. [32] Therefore, the athermal a¢-martensite (£10 vol pct) was formed during cooling of the sample from room temperature down to 213 K (À60°C). Due to the sigmoidal shape of the stressstrain curves, the work-hardening rates observed at the testing temperatures of 213 K and 293 K (À60°C and 20°C) show an increase and a maximum of hardening during the plastic deformation, which is known to be attributed to the deformation-induced a¢-martensite formation.…”

Influence of the Sulfur Content on the Sintering Behavior and the Mechanical Properties of a CrMnNi‐TWIP‐Steel

“…The content of the a 0 -martensite and/or the twins increases with ongoing deformation and causes the high strength of the steel. [1][2][3] Generally there is no high concentration of sulfur in steel alloys, caused by its poor solubility within the alloys and its ambition to form precipitations at grain boundaries, which degrade the mechanical properties of the steel. Detailed investigation of the sulfur concentration in a steel alloy on the shape of the sulfur precipitation and the fracture behavior were carried out by Xiao et al [4] However, in relation to the generation of high alloyed steel powder, sulfur is decreasing the surface tension of steel melts, which was experimentally measured by Dubberstein et al [5] using the maximum bubble pressure method.…”

Casting of Fe–CrMnNi and ZrO2‐Based Metal–Matrix Composites and Their Wear Properties

“…The melt was prepared in a 30 kg‐induction furnace equipped with an argon top purge. As MM, a high‐alloyed metastable austenitic–martensitic CrMnNi16‐6‐3‐steel (16% Cr, 6% Mn, and 3% Ni) was chosen which provides an M s ‐temperature of 61 °C in its as‐cast state and can therefore easily transform to martensite if load is applied . Dubberstein et al measured its melting point using differential scanning calorimetry at 1441 °C, while Kovalev et al calculated a phase composition at room temperature (RT) of 16% (retained delta) ferrite, 21% martensite, and 63% austenite.…”