1: Brief Introduction Of 440C 

Grade 440C stainless steel is a high carbon martensitic stainless steel. It has high strength, moderate
corrosion resistance, and good hardness and wear resistance. Grade 440C is capable of attaining, after
heat treatment, the highest strength, hardness and wear resistance of all the stainless alloys. Its very high
carbon content is responsible for these characteristics, which make 440C particularly suited to such
applications as ball bearings and valve parts.
Corrosion Resistance:
*Good resistance to the atmosphere, fresh water, foods, alkalies and mild acids. Best resistance in the
hardened and tempered and passivated condition. A smooth polished surface also assists.
*The corrosion resistance of grade 440C approximates that of grade 304 in many environments.
Heat Resistance:
*Not recommended for use in temperatures above the relevant tempering temperature, because of
reduction in mechanical properties by over-tempering.
Heat Treatment:
*Annealing - Full anneal - 850-900°C, slow furnace cool to about 600°C and then air cool. Sub-critical
Annealing - 735-785°C and slow furnace cool.
H*ardening - Heat to 1010-1065°C, followed by quenching in warm oil or air. Oil quenching is necessary
for heavy sections. Immediately temper at 150-370°C to obtain a wide variety of hardness values and
mechanical properties as indicated in the accompanying table.
*Tempering in the range 425-565°C is to be avoided because of reduced impact resistance and
corrosion resistance. Tempering in the range 590-675°C results in lower hardness (the product become
machinable) and high impact resistance.
Welding:
*If welding is necessary pre-heat at 250°C and follow welding with a full anneal. Grade 420 filler will give
a high hardness weld (although not as high as the 440C), but 309 or 310 will produce soft welds with
higher ductility.
Machining:
*In the annealed condition this grade is relatively easily machined; approximately the same as for high
speed steel. Chips are tough and stringy so chip breakers are important. If these grades are hardened
machining becomes more difficult and probably impossible.
Other Grades:
201,202,21-4N,301,302,301L,303,303Se,304,304L,304H,304LN,304N,305,S38400,308,309,309S,310,310s,
316,316L,316H,316Ti,316N,316LN,317,317L,317LMN,317LN,321,321H,347,347H,S3100,S31803,S3205,
S32304,S31200,S31260,S32507,405,409,429,430,430F,434,444,403,410S,410,416,420,420F,431F,440A
440B,440C,440F,610,630,631,632,635,660,Alloy 200,Monel 400 ,Alloy K-500 ,Inconel 600 , Incconel 601,
Inconel 625 , Inconel 718 , Alloy 800 ,Alloy 800H,Alloy 800HT,Inconel 825,Alloy 276, Alloy 20, Alloy 59

2: Chemical Composition  3: Stainless Steel Plate/Coil/Flat Bar Process 

4:Stainless Steel Plate/Flat Bar Package 

5: Company Introduction