Hardenability of Stainless Steel

For the martensitic chrome-nickel stainless steel, usually in need of quenching - heat treatment. In the process of adding different amount of alloying elements on the hardening of a different effects.

Quenching on the martensitic stainless steel during quenching from 925-1075°C temperature. The phase change fast, so whether it is oil cooled or air-cooled can be fully hardened. Also in the tempering process must be carried out, due to different tempering conditions available a wide range of different mechanical properties.

In the martensitic chromium stainless steel, due to the addition of chromium to improve iron-carbon alloy hardenability, and thus the need for hardening steel is widely used. The main role of chromium can reduce hardening of the critical cooling rate, hardenability of the steel has been markedly improved. C curve from the point of view, due to the addition of chromium to slow down the rate of change in austenite, C curve was shifted to the right.

In the martensitic chrome-nickel stainless steel, nickel addition can increase the hardenability of steel and can be hardenability. Close to 20% chromium steel in if no quenching ability of nickel added, add 2%-4% of the nickel-recoverable quenching ability. But not too high content of nickel, Or high nickel content will not only expand the γ phase region, but also reduce Mn temperature, so that a single-phase austenitic steel also lose quenching capacity. Select the appropriate nickel content, can increase the stability of martensitic stainless steel tempered, and reduce the degree of temper softening. In addition, martensitic chromium nickel molybdenum stainless steel to increase the temper added stability.

Although the ferrite stainless steel at high temperature does not produce the austenite, and therefore can not be achieved by hardening by quenching, but some low-chromium steel martensitic transformation occurs.

Austenitic stainless steel is Fe-Cr-Ni system and Fe-Cr-Mn system, the austenite. Therefore, from low to high temperature showed a large range of high strength and good extension properties. Can be carried over from the beginning of 1000 ℃ melt processing of solid quench to get all the non-magnetic austenite, resulting in good corrosion resistance and maximum elongation.

Directory | Standard | Heat | Heat Exchanger | Temperature | Pressure | Corrosion | Hardness | Surface | Properties | Select Stainless Steel | Contact US