Pipa Baja Tahan Karat 409L 409 Baja Tahan Karat
ASTM A268 409 409L 1.4512 stainless steel is an alloy designed principally for the automotive exhaust industry, although it has been used successfully in other industrial applications. It combines good elevated suhuketahanan korosi with medium strength, good formability and overall cost. 409L stainless steel is highly resistant to high temperatures, achievable engine and exhaust systems, and reduces the thickness of the exhaust system to reduce exhaust emissions. Low cost, good flexibility, high yield, easy replacement, and environmentally friendly new products.
409 Stainless Steel is a titanium stabilised feritik stainless steel. Although regarded as a general-purpose chromium stainless steel the primary application for Grade 409 is automotive exhaust systems. Its applications are those where appearance is a secondary consideration to sifat mekanik dan korosi resistance and where some weldability is required.
Type 409 is a baja tahan karat feritik that has a good combination of heat resistance and ketahanan korosi. Its titanium stabilized low nikel content provides for an economical metal to corrosion resistance and ketahanan oksidasi .
More highly stabilised versions of 409 are useful where 409 has been proven marginal – these grades S40910, S40920 and S40930 are stabilised with titanium, niobium or both titanium and niobium. Used to automobile mufflers, catalytic converters, tailpipes, farm equipment, structural supports and hangers, transformer cases, diamond tread plate and shipping containers.
Magnetic Properties: 409 flat rolled stainless steel is magnetic and cannot be hardened by heat treatment. It can, however, be somewhat hardened by cold-working. Type 409 has great keuletan and is suitable for use in deep draw applications. It is also easily formable.
Chemical Composition of ASTM A268 409 S40900 Grade and EN 10088-2 1.4512 1.4516 Stainless Steel
| Kelas | – | C | Mn | Si | P | S | Cr | Ni | Ti |
| A268 409 | min. maks. | – 0.08 | – 1.00 | – 1.00 | – 0.045 | – 0.030 | 10.5 11.7 | – 0.50 | 6×C-0.75 |
| TP409L | min. maks. | – 0.035 | – 1.00 | – 1.00 | – 0.045 | – 0.030 | 10.5 11.7 | – 0.50 | 6×C-0.75 |
| 1.4516 | min. maks. | – 0.08 | – 1.50 | – 0.70 | – 0.040 | – 0.015 | 10.5 12.5 | 0.50-1.50 | 0.05-0.35 |
| 1.4512 | min. maks. | – 0.030 | – 1.00 | – 1.00 | – 0.040 | – 0.015 | 10.5 12.5 | – 0.50 | 6×(C+N)-0.65 |
Mechanical properties of ASTM A268 409 Grade and EN 10088-2 1.4512 stainless steel
| Kelas | Kekuatan Tarik | Kekuatan Hasil 0.2% Proof | Perpanjangan | Kekerasan | Kekerasan |
| Kelas | ksi(MPa) min | ksi (MPa) min | (% dalam 50mm) min | Rockwell B (HR B) maks | Brinell (HB) maks |
| 409 | 55 (380) | 25 (170) | 20 | 95 | 207 |
| 1.4512 | 380-560 | 210 | 25 |
Typical physical properties for annealed grade 409 stainless steels are given in table 3.
Tabel 3. Physical properties of 409 grade stainless steel in the anil condition
| Kelas | Kepadatan (kg/m³) | Modulus Elastisitas (GPa) | Koefisien Rata-rata Thermal Expansion (mm/m/°C) | Koefisien Rata-rata Thermal Expansion (mm/m/°C) | Koefisien Rata-rata Thermal Expansion (mm/m/°C) | Konduktivitas Termal (W/m.K) | Konduktivitas Termal (W/m.K) | Specific Heat 0-100°C (J/kg.K) | Tahanan Listrik (nW.m) |
| 0-100°C | 0-315°C | 0-538°C | pada suhu 100°C | pada suhu 500 ° C | |||||
| 409 | 7600 | 208 | 11.0 | 11.7 | 12.4 | 25.8 | 27.5 | 460 | 600 |
Grade Specification Comparison
Approximate grade comparisons for 409 stainless steel are given in table 4.
Tabel 4. Grade specifications for 409 grade stainless steel
| Kelas | UNS | BS | BS | EN | EN | Swedia | Bahasa Jepang |
| – | Tidak. | EN | Nama | SS | JIS | ||
| 409 | S40900 | 409S19 | – | 1.4512 | X6CrTi12 | – | SUH 409 |
Perbandingan ini hanya merupakan perkiraan saja. Daftar ini dimaksudkan sebagai perbandingan bahan yang secara fungsional serupa tidak sebagai jadwal yang setara dengan kontrak. Jika diperlukan ekuivalensi yang tepat, spesifikasi asli harus dikonsultasikan.
Possible Alternative Grades
Possible alternative grades to grade 409 stainless steel are given in table 5.
Tabel 5. Possible alternative grades to 409 grade stainless steel
| Kelas | Why it might be chosen instead of 409 |
| 3CR12 | Similar corrosion resistance, easier welding and more readily available than 409, particularly in heavy sections. (409 may have better drawability than 3CR12.) |
| 304 | Better corrosion resistance and heat resistance but at higher cost. |
| 321 | Higher heat resistance than 409 or 304. |
| Aluminised steel | Lower resistance to exhaust gases, but at lower cost than stainless steel grade 409. |
Ketahanan Korosi
Grade 409 resists atmospheric and exhaust gas korosi. A light surface rust will form in most atmospheres; this rust retards further corrosion but makes the surface undesirable for decorative applications. The corrosion resistance is about the same as that of 3CR12 and the 12% chromium martensitic grades such as 410, and inferior to the 17% chromium grade 430.
Tahan Panas
Generally 409 is classified as resistant to scaling in intermittent service up to 850°C and up to 650°C in continuous service, but these temperatures are dependent upon the exact service environment.
Perlakuan Panas
Anil – panas to 790-900°C and air cool. This grade cannot be hardened by thermal treatment.
Pengelasan
Readily welded but a pre-heat of 150-260°C is recommended. Grade 409 or Grade 430 electrode or filler rods can be used, but AS 1554.6 pre-qualifies welding of 409 with Grade 309 rods or electrodes. These austenitic fillers result in a more ductile weld.
Post-weld annealing at 760-815°C improves weld ductility.
Post-weld annealing is not required when welding thin sections. Automotive exhaust tubing is typically welded without filler metal (autogenously).
All welding must be carried out with minimum heat input to reduce grain growth effects.
Aplikasi
Aplikasi yang umum meliputi:
• Automotive exhaust systems
• Catalytic converters
• Mufflers
Referensi Terkait:
1. Baja Tahan Karat Superferitik
2. Baja Tahan Karat Ferit Feritik
3. Tabel Perbandingan Nilai Baja Tahan Karat Feritik
4. Dibandingkan dengan baja tahan karat feritik, baja tahan karat dupleks rentan
5. Baja Tahan Karat Tahan Panas 409L