Martensitic stainless steels, like ordinary alloy steels, have the characteristic of being hardened by quenching, so a wide range of different mechanical properties can be obtained by selecting grades and heat treatment conditions.
Martensitic stainless steel from a large area to distinguish, are iron - chromium - carbon stainless steel. And then can be divided into martensitic chromium stainless steel and martensite chromium nickel stainless steel. The trend of strength change when adding elements such as chromium, carbon and molybdenum into martensitic chromium-based stainless steel and the strength characteristics of nickel added to martensite chromium-nickel-based stainless steel are as follows.
Martensitic chromium stainless steel In the quenching - tempering conditions, increasing the content of chromium ferrite content can increase, which will reduce the hardness and tensile strength. Low-carbon martensitic chromium stainless steel in the annealing conditions, when the chromium content increased hardness increased, while the elongation decreased slightly.
Under the condition of certain chromium content, the increase of carbon content also increases the hardness of steel after quenching, while the plasticity decreases. The main purpose of adding molybdenum is to improve the strength, hardness and secondary hardening effect of the steel. After low-temperature quenching, the addition of molybdenum effect is very obvious. The content is usually less than 1%.