The ferritic stainless steels are identified by 400 Series numbers. These straight-chromium alloys are not hardenable by heat treatment and only slightly hardenable by cold working.
Main ultra-pure ferrite grades and quantitative requirements, production cycle Representative ultra-pure ferrite grades: 439, 443M, 444, 446, 445J1, 445J2.
MOQ Requirement: 439, 443M, 444 need more than 16 tons to set the production cycle 55-60 days.
446, 445J1, 445J2 need more than 60 tons, the production cycle is 100 days.
Utral-pure Ferritic is refers to the gap element such as carbon,nitrogen content of ferritic stainless steel wich are very low, C+N≤120ppm-400ppm(250ppm,150ppm)，at any temperature,its mircrostructure is ferritic structure,chromium content of 17%-30% and 0-4% molybdenum content of iron base chrome molybdenum alloy.
409L、444、436L and so on hyperpure ferritic stainless steel,
The current development of steel grades: exhaust system (409 l, 429, 436 l, 439 m, 441), decoration (439, 443), water system (444、445/445J1/445J2）/446
ASTM A268 Standard Specification for Seamless and Welded Ferritic and Martensitic Stainless Steel Tubing for General Service
JIS G3463 Stainless Steel for Boiler and Heat Exchanger Tubes
GB/T 30065 Welded ferritic stainless steel tubes for feedwater heater
GB/T 30066 Welded ferritic stainless steel tubes for heat-exchanger and condenser
A, good resistance to stress corrosion, all kinds of partly corrosion resistance and good oxidation resistance medium uniform corrosion ability (including high temperature oxidizing)
B, low density, under the condition of the same weight, material can be saved 2.5%
C, heat conduction performance is good
D, small thermal expansion coefficient
E, the large modulus of elasticity
F, good processing performance
1. The cold hardening tend to be low, for larger cold deformation, generally without intermediate annealing
2. Easy to cold bending, stamping, beading, pressure testing, cold forging and cutting
3. Good deep drawing performance.
Equipment & Techlogy: