1. 439 Introduction
The 439 steel grade reduces the C content on the basis of ordinary ferrite materials (430), while adding stabilizing elements such as Ti to improve the intergranular corrosion resistance, formability and weldability of the steel grade. Compared with 304 steel, although its elongation is lower (about 30%), its strength and corrosion resistance are equivalent, and its corrosion resistance is better than that of 200 series materials.
Chemical Composition
| Country | Standard | Grade | Chemical Composition（％） | ||||||||
| C | Si | Mn | P | S | Cr | Ni | N | Ti | |||
≤ | |||||||||||
Amercia | ASTM | 439 | 0.03 | 1.00 | 1.00 | 0.04 | 0.03 | 17.0- 19.0 | ≤ 0.5 | ≤ 0.04 | 0.2+4(C+N)－1.10 |
| Gernmany | DIN | 1.4510 | 0.05 | 1.00 | 0.00 | 0.04 | 0.015 | 16.0-18.0 | – | – | 4(C+N)－0.80 |
2. Mechanical Properties
Standard | Mechanical behavior | |||
| TS | YS | Elongation | Hardness | |
| N/m㎡ | (≤)N/m㎡ | （≥）％ | （≤）HV | |
ASTM | ≥415 | 205 | 22 | 180 |
| DIN | 420－600 | 230 | 23 | |
3. Main Purpose
Decorative panels for elevators and escalators
Architectural decorative panels, such as decorative structural parts, structural pipes
Component of automobile exhaust system
The inner drum of the washing machine”