Martensite is a very hard form of steel crystalline structure. It is named after German metallurgist Adolf Martens . By analogy the term can also refer to any crystal structure that is formed by diffusionless transformation .

untempered martensite have been written by Cohen [3–5] and Owen [6], but because of the high mobility of carbon, the explanations developed have been based on experiments in iron–nickel–carbon alloys where carbon diffusion can be suppressed because of subzero Ms temperatures. Christian [7] has also reviewed the

1999年12月15日 · The evaluation of strengthening in these alloys has been limited to interpreting yield strength of unaged, untempered martensite in terms of interstitial solid solution strengthening. The second section reviews strengthening of martensitic Fe–C alloys and low-alloy carbon steels with above-room-temperature M s temperatures.

The residual phase is untempered martensite which etches lighter because of the absence of carbide precipitates. It is follows that it is easy, using optical microscopy, to distinguish bainite and martensite as long as both phases are presente in the microstructure.

Untempered martensite. Untempered martensite is a strong, hard, brittle material. The stronger and harder it is, the more brittle it is. The strength and hardness is a due to elastic strains within the martensite, a result of too many carbon atoms being in …

2023年10月10日 · In this paper, low- and high-strength lath martensite (350 and 640 HV) was fabricated in an IF steel via high pressure martensitic transformation. The microstructure and the softening during their tempering from 200 °C to 800 °C for 1 h were systematically investigated.

It was found that all the untempered regions in the martensitic microstructure were oriented with the plane normals {100} close to the thickness, or normal, direction of the plates. Variant analysis revealed that the untempered regions and the auto-tempered regions are part of the same packet.

2016年9月15日 · In the present investigation, the dislocation density of untempered martensite was estimated using a synchrotron X-ray measurement at the 33-ID-D beamline of the Advanced Photon Source (APS) at the Argonne National Laboratory.

2014年1月22日 · The hardness of untempered martensite depends almost solely on carbon content, but the influence of carbon on the hardness of tempered martensite decreases markedly as the tempering temperature is increased.

A complete mechanism of tempered martensite embrittlement is proposed involving i) precipitation of interlath cementite due to partial thermal decomposition of interlath films of retained austenite, and ii) subsequent deformation-induced transformation on