Metal for automatic lathes
 
Martensitic stainless steels are in the y phase zone at normal quenching temperature, but their y phase is only stable at high temperatures, and the M point is generally around 300 °C, so it is transformed into martensite when cooling.
Martensitic stainless steels include 2Cr13, 2Cr13Ni2, 3Cr13 and partially modified 12% chromium hot strength steel, such as 13Cr14NiWVBA, Cr11Ni2MoWVB steel, etc. The mechanical properties, corrosion resistance, process properties and physical properties of martensitic stainless steel are similar to ferritic-martensitic stainless steel containing 12~14% chromium. Since there is no free ferrite in the tissue, the mechanical properties are higher than those of the above steels, but the overheat sensitivity during heat treatment is lower.
 
Martensitic stainless
steel   Standard               AISI、ASTM
Model No.416                  UNS number  S41600
●416 characteristics and applications: 416 is martensitic stainless steel, the domestic grade is Y1Cr13, is the best steel grade in stainless steel. 416 is used for automatic lathes, etc. Free-cutting stainless steel is mainly used in the production of electromagnetic, micro motor and electrical components.
●416 Chemical composition (0): carbon C: ≤15.1 manganese Mn: ≤ 25.1 silicon Si: ≤ 00.12 chromium Cr: 0.14~0.0 nickel Ni(06):— phosphorus P: ≤0.15 sulfur S: ≤<>.<> Note: (<>) Divide a single value
Unless otherwise indicated, all are the highest values;
(2) When used in some pipe making processes, the nickel content of some models of austenitic stainless steel must be slightly higher than the value shown in the table;
(3) casual;
(0) The maximum Ta content is 10.<>%;
(0) The highest content is 75.<>%;
(0) The maximum content is 70.<>%
Martensitic stainless steels have the same characteristics as ordinary alloy steels to achieve hardening by quenching, so a wide range of different mechanical properties can be obtained by selecting grades and heat treatment conditions.
Martensitic stainless steel is distinguished from a large aspect and belongs to iron-chromium-carbon stainless steel. It can be further divided into martensitic chromium stainless steel and martensitic chromium-nickel stainless steel. The trend of strength when adding elements such as chromium, carbon and molybdenum to martensitic chromium stainless steels
The strength characteristics of nickel added to martensitic chromium stainless steels are described below:
1. Under the condition of quenching-tempering, increasing the chromium content of martensitic chromium stainless steel can increase the ferrite content, thereby reducing the hardness and tensile strength, but improving the plasticity.
2. Under the condition of annealing, the hardness of low-carbon martensitic chromium stainless steel increases when the chromium content increases, while the elongation decreases slightly.
3. Under the condition of a certain chromium content, the increase of carbon content increases the hardness of steel after quenching, and the plasticity decreases.
4. The main purpose of adding molybdenum is to improve the strength, hardness and secondary hardening effect of steel. After low-temperature quenching, the addition effect of molybdenum is very obvious. The content is usually less than 1%.
5. In martensitic chromium-nickel stainless steel, a certain amount of nickel can reduce the ferrite content in the steel and make the steel obtain the maximum hardness value.
The chemical composition of martensitic stainless steel is characterized by the addition of molybdenum, tungsten, vanadium, niobium and other elements on the basis of different component combinations of 0.1%-1.0% carbon C and 12%-27% chromium Cr. Since the tissue structure is a body-centered cubic structure, the strength decreases sharply at high temperatures. And while
Below 600 °C, the high temperature strength is the highest among all types of stainless steel, and the creep strength is also the highest.