Full Transcript:

What’s up guys?!?!? This is Michael with Michael Talks Metal back for another grammar lesson. I mean metals, we’re talkin about metals. BUUUUUUUTTTTTTTT……. Today our video will begin with our ABC’s………  440 A,  B , and C that is.

Type 440 has these three versions that differ in carbon content; A having the lowest and C having the highest carbon.  Heat treated hardness capability increases with the increase of carbon. This week we will focus on 440A for aerospace applications.

440A  has the UNS designation S44002. It is a martensitic alloy that can be heat treated to higher hardness and strength levels than type 420 due mainly to its higher carbon content.

Typical applications require its increased strength and hardness and where the oxidation and corrosion resistance of this 17% chromium alloy is required.

Typical annealing temperature  is from  1550 to 1650 deg F followed by slow cooling.

Typical hardening range is 1800 to 1950 deg F followed by an air or oil quench depending on section size. Temper as required for desired hardness

Maximum corrosion resistance is achieved in the fully hardened condition.

Is 440A is magnetic? Yes, 440A IS magnetic.

440A – SAE 51440A UNS S44002

Density:      point 28 lbs per cubic inch

Mean Coefficient of Thermal Expansion from 32 -212 deg F:

5.7 microinch per inch per deg F

Machinability rating: 40 %   (of 1212)

Chemical Composition:

Carbon            0.60 – 0.75 %

Manganese      1.00 % Max

Silicon              1.00 % Max

Phosphorus      0.040 % Max

Sulfur                0.030 % Max

Chromium        16.00 – 18.00 %

Nickel                0.75 % Max

Molybdenum     0.75 % Max

Copper              0.50 % Max

Typical maximum hardness in the annealed condition:  241 BHN

Response to heat treatment in standard sample: 55 RC Minimum

Specifications for annealed condition:

AMS 5631: Bars and Forgings

AMS-QQ-S-763  Bars, Shapes, and Forgings

ASTM and ASME standards for commercial applications are too numerous to detail here.

Refer to our website for more information and videos on stainless steels. Additional specifications and part requirements can alter what we have shown you here today. SO CHECK THE SPECS !!!!!!!!!!!  Check out the earlier videos on stainless steels and visit us at our website at  www.michlinmetals.com. Michlin Metals is a distributor and supplier of 440A. Thanks for watching this is Michael with Michael Talks Metal. If you made it this far and haven’t subscribed