Topic
Pearlite
About: Pearlite is a research topic. Over the lifetime, 6028 publications have been published within this topic receiving 65695 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the interplay of process variables in terms of peak temperature and cooling rate was studied to observe their effect on joint efficiency under shear testing, and the peak hardness at weld nugget was close to the parent alloy at an intermediate cooling rate of 294 to 313 k/s.
Abstract: Advanced high-strength M190 steel sheets were joined by friction-stir welding under different tool rotational and traversing speeds. The optical microstructure of the joints exhibited complete martensite and partial martensite at the weld nugget depending on the cooling rate during welding. The first heat-affected zone outside of the weld nugget revealed ferrite-pearlite phase aggregate, and the second heat-affected zone showed a tempered martensitic structure. The interplay of process variables in terms of peak temperature and cooling rate was studied to observe their effect on joint efficiency under shear testing. The peak hardness at weld nugget was close to the parent alloy at an intermediate cooling rate of 294 to 313 K/s. The lowest hardness was observed at the first heat-affected zone for all welded joints. Joint efficiency was dependent on relative quantity of ferrite-pearlite at first heat-affected zone. In that respect, the intermediate temperature to the tune of ~1193 K to 1273 K (~920 °C to 1000 °C) at the weld nugget was found to be beneficial for obtaining an adequate quantity of pearlite at the first heat-affected zone to provide joint efficiency of more than 50 pct of that of parent alloy.
23 citations
TL;DR: In this paper, the authors investigated the fatigue crack propagation behavior of three thermomechanical control process steels with different microstructures but similar yield strengths of approximately 450 MPa.
Abstract: In the present study, stress (S) – number of cycles to failure (N) (S–N) fatigue and fatigue crack propagation behaviors of three thermomechanical control process steels with different microstructures but similar yield strengths of approximately 450 MPa were investigated. The P + F steel was predominately pearlite plus ferrite, whereas B1 and B2 steels were both bainitic steels with martensite-austenite and pearlitic islands. Despite the significant difference in microstructural features, the resulting fatigue crack propagation rates and near-threshold ΔK values were comparable with each other. The hard phases, such as pearlite colonies in the P + F specimen, tended to affect fatigue crack propagation behavior in a similar manner, and severe crack branching was observed in intermediate and high ΔK regimes. Despite similar fatigue crack propagation rates and near-threshold ΔK values, the resistance to S–N fatigue was substantially different for each steel specimen. Depending on fatigue crack initiators, such as the ferrite/pearlite phase boundaries for the P + F specimens and the cracked martensite-austenite and/or small pearlitic islands for the bainitic specimens, the cycles for crack initiation varied greatly.
23 citations
TL;DR: In this paper, the effect of prior microstructures on the behavior of cementite particles in conjunction with microstructural changes of the matrix during subcritical annealing was investigated by changing the initial micro-structures into ferrite + coarse pearlite, ferrite-pearlite, bainite, and martensite.
Abstract: The effect of prior microstructures on the behavior of cementite particles in conjunction with microstructural changes of the matrix during subcritical annealing was investigated by changing the initial microstructures into ferrite + coarse pearlite, ferrite + fine pearlite, bainite, and martensite, in medium carbon steels. While the coarsening of cementite particles in martensite proceeded rapidly with the growth of large cementite particles at boundaries with the dissolution of smaller particles within martensite laths, the coarsening rate of cementite particles in bainite was found to be much slower than that in martensite. This could be attributed to the thermal stability of cementite particles, the smaller amount of carbon in solution, and the lower driving force for solute diffusion due to the uniform size distribution of cementite particles in bainite. The controlling coarsening kinetics in medium carbon steels with ferrite-pearlite, bainite and martensite, were found as boundary diffusion, diffusion along dislocation, a combination of boundary diffusion and diffusion along dislocation, respectively.
23 citations
TL;DR: In this article, the authors applied synchrotron X-ray diffraction to study the evolution of lattice strain and stresses in both phases of pearlitic steel during a tensile test.
23 citations
TL;DR: In this paper, the microstructural characteristic of HSLA welds containing different amounts of titanium were evaluated carefully and it was observed that the microstructure of welds consisted of ferrite with mixed morphologies, and small amounts of pearlite and martensite-austenite micro-constituents.
23 citations