“Towards efficient microstructural design and hardness prediction of bearing steels—An integrated experimental and numerical study.” Materials & Design 133 (2017): 464-475.
Marquenching oils have a higher flash point so that they can be heated to high temperatures (~500°F). However, it has become somewhat fashionable to talk about knife performance as entirely (or almost entirely) controlled by the knifemaker’s skill in heat treatment. However, in a TTT for W1 the bainite transformation is a significant part of the diagram. It doesn’t. The day you posted this I was taking a short test on hardenability at university. When most people think of quenching, they probably picture a blacksmith dropping a red-hot piece of steel into a bucket of water. However, if the steel transforms to a different phase then deviations are observed as the steel cools. At intermediate rates the steel also passes through the “B” field which represents bainite. S2 – 0.75C-0.5Mn-1.2Si-0.55Mo-0.2V [11] – A good example of the effect of Mo, which has a strong effect on high temperature transformations (ferrite-pearlite) but has little effect on bainite, so medium cooling rates can lead to bainite formation. Below shows the retained austenite for different cold treatments after different delay times at room temperatures. Here is a chart of retained austenite contents and hardness values achieved with and without cryo with low alloy steels: Now just because the retained austenite can be reduced with cryo doesn’t mean that you have to do so. are also air hardening steels due to the Mo additions plus high Cr. This is probably as good a point as any to discuss the quenching medium. W2 steel [11] – 1.0C-0.2Mn-0.2Si-0.1V – Very low hardenability, needs to be quenched in 3 seconds, W1 – 1.05C-0.25Mn-0.2Si – Very low hardenability, 0.70C-0.25Mn-0.25Si [5]- 1070 though with lower Mn than normal (typically around 0.7Mn).
Here is an example of a steel cooling slowly to form ferrite and the remaining austenite transforms to pearlite: The points where the line deviates are the start and end of the different transformations, so those transformation temperatures can be determined with dilatometry. For both, the carbon factor would be about 0.61. Newly formed maretniste puts compressive stress on the remaining austenite. a blacksmith plunges an axe or hatchet into cold water to temper it—for it is this that gives strength to the iron . See the chart below for carbon and chromium “in solution” during holding of 52100 at 1545°F: You can see that the change in C/Cr in solution is very rapid within the first few minutes, and trying to target a specific hardness would be challenging if you are trying to hold for very short times, especially under 5 minutes. In most materials science phase diagrams we only graph composition and temperature because we assume that the pressure is just the atmospheric pressure, but internal stresses act the same as an external pressure. More common is to use “quench plates” where the knife is placed between two aluminum plates and the heat is drawn out through conduction, significantly faster than still air alone. No heat treatment can turn 1095 carbon steel into a stainless.