Grade about normal precipitation hardening hot rolled Stainless steel coils
S17400 17-4PH 0Cr17Ni4Cu4Nb
S15500 15-5PH 0Cr15Ni4Cu4Nb
S17700 17-7PH 0Cr17Ni7Al
S17400 Chemical component ASTM A564
C：≤0.07 ，Si ：≤1.0 Mn：≤1.0 ，Cr：15.0～17.5 ，Ni：3.0～5.0， S ：≤0.03 ，P ：≤0.04 Cu: < 3.0～5.0
S17400 mechanical property ASTM A564
Tensile strength : > 1310 Mpa
Yield Strength : >1170 Mpa
Elongation (%): > 35%
Hardness: > Brinell 388
Define about precipitation hardening hot rolled Stainless steel
Precipitation hardening (precipitation hardening): A heat treatment process in which a metal in a supersaturated solid solution is segregated in a solute atom and/or in which dissolvable particles are dispersed and dispersed in the matrix to cause hardening. If austenite precipitated stainless steel is subjected to precipitation hardening at 400-500°C or 700-800°C after solution treatment or after cold working, high strength can be obtained. That is, the supersaturated solid solution of some alloys is left at room temperature or heated to a certain temperature. The solute atoms will accumulate in a certain area of the solid solution matrix or form a second phase, resulting in an increase in the hardness of the alloy.
Precipitation hardening stainless steel and its classification
Precipitation-hardening stainless steel was developed by the United States Steel Corporation in the 1940s. It has high strength after precipitation hardening heat treatment, plasticity and corrosion resistance is superior to other stainless steel.
Precipitation-hardening stainless steels can be classified into martensitic, semi-austenitic and austenite types according to the metallographic structure of the matrix.
(1) Martensitic type
Martensitic precipitation-hardening stainless steels are usually supplied in the martensitic state and undergo precipitation hardening after a simple aging treatment. The properties of martensite precipitation hardened stainless steel can be obtained by one or both of martensite formation and precipitation hardening mechanisms. It is the most widely used steel for precipitation hardening stainless steels.
(2) Semi-austenitic type
The substrate of the semi-austenitic stainless steel is austenite and contains 5% to 20% of delta ferrite. Through special heat treatment before hardening, the austenite is transformed into martensite and then subjected to aging treatment. Semi-austenitic stainless steels can be processed into a variety of products, but are mainly used for flat-rolled sheets and strips. This precipitation-hardening stainless steel is generally not used in valve products.
(3) Austenite type
Austenitic stainless steels are supplied in austenitic conditions and these steels are rarely used