This kind of steel is lower than the room temperature, after solid solution treatment for austenitic organization, easy to forming and welding. Usually can use two kinds of process of martensitic stainless steel stick shift. Is a solid solution treatment after heating by 700 ~ 700 degrees, austenitic stainless steel square bar for chromium carbide precipitation into medium stable state, Ms point rise above to room temperature, cooling into martensite stainless steel square rod; The second is to cool down after solid solution treatment directly to between Ms and Mf, transformation of austenite to martensite. After a method can obtain higher corrosion resistance, but after solid solution treatment and cryogenic interval time shoulds not be too long, otherwise it will due to the aging stability of austenitic stainless steel square bar and decreases the reinforcement effect of cryogenic. After the above processing steel aging then through 400 ~ 400 degrees, the precipitation intermetallic compounds into step – reinforcement. Typical of this kind of steel steel grade 17 cr 7 ni one A1, 15 cr – ni – 9 A1, 17 cr – 5 15 8 ni – cr – ni – Mo, Mo a A1, etc. This kind of steel is also known as austenitic stainless steel square bar – maraging stainless steel, and because, in fact, the steel in the organization in addition to the austenite and martensite, there are different amounts of ferrite, therefore, also known as half austenitic precipitation-hardening stainless steel.
This kind of steel is the late 50 s development and application of new type stainless steel stainless steel rods, they are the general characteristics of high strength (C to 100 a 100) and hot strong sex good, but because of the low amount of chromium and chromium carbide precipitates frequently in heat treatment, and therefore corrosion resistance than the standard austenitic stainless steel square rod lower. Can say this kind of high strength steel is in sacrifice part of corrosion resistance and other properties (e.g., non-magnetic), under the condition of this kind of steel is mainly used in aviation industry and the rocket missile production, usually it is not widely used in machinery manufacturing, and also have them on classification for a series of ultra-high strength steel.