630 (17-4) Precipitation Hardening Stainless Steel Bar
It is characterised by high tensile strength and high yield strength obtained by solution annealing, followed by a single or double low temperature (precipitation) age hardening treatment. Coupled with a corosion resistance comparable to 304 austenitic stainless steel in many corrosive environments.630 in the H1075 (H580) aged condition can be re-aged if necessary at a higher temperature simply by heating at the required temperature for the required duration.630 in the H1075 (H580) And H1150 (H620) aged condition, can also be re-aged at a lower temperature by re-solution annealing, followed by age hardening at the required temperature for the required duration.It is used extensively by the Marine, Aerospace, Chemical, Petrochemical, Food Processing, Paper and general metalwork industries. Here it is employed for applications such as: Pump Shafts, Aircraft Fittings, Valve Stems, Hydraulic Fittings, Studs, Bushings, Screws, Fasteners, Couplings, Wear rings, Rollers and Food Handling Equipment etc..
Material Magnetic in all conditions.
|Colour Code||Stocked Sizes|
|Min. %||Max %|
|UTS Mpa (Min)||1170||1070||1000||965||930||795||860|
|Yield Mpa (Min)||1170||1070||1000||860||795||725||502||725|
|Elongation % in 50mm (Min)||10||10||12||13||14||16||18||16|
|Hardness||Rc||38 Max||40||38||35||32||31||28||24||24||33 Max|
|BHN||363 Max||388||375||331||311||302||277||255||255||331 Max|
|Impact Charpy - V||ft/lbs (Min)||5||15||20||25||30||55||30|
|Elongation % in 50mm||15||14||14||15||16||17||19||22||20|
|Impact Charpy - V||ft/lbs||30||15||25||35||40||45||50||100||90|
|Finished forgings should be cooled in air to below 90oF (32oC) prior to further processing in order to obtain optimum grain size and mechanical properties.Finally forgings will require to be solution annealed prior to age hardening as required.|
|Air Cool To Below 90oF (32oC)*Actual holding time should be long enough to ensure that the part is heated thoroughly through out its sectionSections over 75mm -|
|Hold for Hours||1||4||4||4||4||4||2||4||4||4|
|Cool to Below||Air||Air||Air||Air||Air||Air||Air||Air||Air||Air|
Therefore to ensure complete transformation to martensite, it is most important that parts are always cooled to below 90oF (32oC) within 24 hours following Solution Annealing and before Age Hardening Treatment which should also be followed by an air cool to below 90oF (32oC).
The age hardening tempers the martensite resulting in an improvement in toughness. The higher the ageing temperature the more refined the martensite leading to greater ductility but slightly lower strength.
N.B. Temperature control is critical during age hardening and any variations outside the given range could lead to less than satisfactory results.
In the solution annealed condition resistance to stress corrosion cracking is low - improving at age hardening temperatures from 1025oF (550oC) upwards to a maximum at 1150oF (620oC) double aged.
|Condition A to condition H1150 (H620) - contraction 0.0009/0.0012 M/M|
|Following welding in the solution annealed condition, parts can be directly age hardened as required, however those in the H1150 (H620) condition should be re-solution annealed and then age hardened as required.|
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