MARTENSITIC STAINLESS STEELS
Martensitic stainless steels are the only group of stainless steels that can be hardened by heat treatment (quenching and tempering). Their carbon content is higher than that of the other stainless groups, and that is what gives them their hardness, wear resistance and cutting ability.
They are magnetic and can be used across a very wide strength range depending on the heat treatment condition. As carbon content rises, hardness rises while corrosion resistance and toughness fall. Martensitic grades are therefore chosen where mechanical strength rather than corrosion resistance is the priority.
They always require heat treatment after welding, otherwise the weld zone becomes brittle. Knives and cutting tools, pump and valve components, shafts, turbine blades and die components are the main applications.
Choosing a grade. For general purpose use where medium hardness is sufficient, AISI 410 is the starting point. For parts that will be welded and need high toughness and good corrosion resistance, low carbon AISI 415 is used. Where machining is extensive, AISI 416 and AISI 430F, whose machinability is improved by a sulphur addition, come to the fore. As the hardness requirement rises, the sequence AISI 420, AISI 420B and AISI 420C follows the increasing carbon content, with the highest hardness in knife and die applications obtained with 420C. For shaft applications requiring high strength together with corrosion resistance, nickel-bearing AISI 431 is the choice.
OUR MARTENSITIC STAINLESS STEEL GRADES
- AISI 410 / (1.4006)
- AISI 415 / (1.4313)
- AISI 416 / (1.4005)
- AISI 420 / (1.4021)
- AISI 420B / (1.4028)
- AISI 420C / (1.4034)
- AISI 430F / (1.4104)
- AISI 431 / (1. 4057)
- AISI 440C / (1.4125)
Tell us the hardness and heat treatment condition you are aiming for and we will identify the right grade together — contact us.