| Jenis Baja | jeneng | JIS (Jepang) | AISI/SAE (USA) | DIN (Jerman) | GB (China) |
|---|---|---|---|---|---|
| Karbon rendah (baja) | Bar baja bunder | SS400 (5541) | A36 | - | Q235 |
| Baja karbon sithik | S15C | SAE 1015 | CK15 (1.1141) | 15 | |
| S20C | SAE 1021 | CIC20 (1.0402) | 20 | ||
| Baja karbon sedheng | Baja karbon sedheng | S45C | SAE 1045 | CK45, C45 (1.0503) | 45 |
| S50C | SAE 1050 | CK50 (1.1213) | 50 | ||
| S55C | SAE 1055 | CK55 (1.1203) | 55 | ||
| Baja paduan Cr-Mo | Bar baja bunder | SCM415 (SCM21) | - | 15CrMo5 (1.7262) | 15CrMo |
| Bar baja bunder | SCM420 (SCM22) | - | 25CrMo4 (1.7218) | 20CrMo | |
| Bar baja bunder | SCM440 (SCM4) | SAE 4140 | 42CrMo4 (1.7225) | 42CrMo | |
| Baja paduan Ni-Cr-Mo | Bar baja bunder | SNCMno (SNCM21) | SAE 8620 | 21NiCrMo2 (1.6523) | 20CrNiMo |
| Bar baja bunder (kanthi kandungan nikel dhuwur) | SNCM420 (SNCM23) | SAE 4320 | 20CrNi2Mo | ||
| Bar baja bunder | SNCM439 (SNCM8) | SAE 4340 | 40NiCrMo6 | 40CrNiMo4 | |
| Baja pinion | _ | 17CrNiMo6 18CrNiMo7-6 | _ | ||
| Baja paduan Al-Cr-Mo | Bar baja bunder | SACM645 (SACM1) | SAE 7140 | 41CrAlMo7 (1.8550) | 38CrMoAl |
| Baja paduan kromium karbon dhuwur | Baja bantalan | SUJ2 | 52100 | (110Kr6 .fteen) | GCr15 |
| Baja perkakas paduan | Baja perkakas kerja dingin | SKD11 | D2 | X165CrMoV12 (1.2601) | Cr12MoV |
| Baja perkakas kerja panas | SKD61 | H13 | X40CrMoV51 (1.2344) | 4Cr5MoSiV1 | |
| Baja dhuwur-kacepetan | SKH51 (SKH9) | M2 | 56-5-2 (1.3343) | W6Mo5Cr4V2 | |
| Baja alat karbon | Bar baja bunder | SK 2 (SK 120) | W1-111/2 | - | |
| SK 3 (SK 105) | W1-10 | C1051,V1 (1.1545) | - | ||
| stainless steel | 303 stainless steel | SUS303 | A1SI 303 | Xl2CrNi5188 (1.4305) | 1Cr18Ni9MoZr |
| 304 stainless steel | SU5304 | AISI 304 | X5CrNi189 (1.4350) | OCr181119 | |
| 316 stainless steel | SUS316 | AISI 316 | X5CrNiMo1810 (1.4401) | OCr17Ni1Mo2 |
Baja minangka salah sawijining bahan teknik sing paling akeh digunakake amarga versatility, kekuatan, kekiatan, Lan kemampuan kanggo alloyed lan panas-dianggep kanggo sawetara saka sudhut aplikasi. Sifate gumantung komposisi kimia, perawatan panas, lan pangolahan.
Sifat Kunci Baja
1. Properti Mekanikal
| Property | Description |
|---|---|
| Kekuatan tarik | Resistance kanggo break ing tension. Range saka 250 MPa (ringan) nganti 2000+ MPa (baja perkakas). |
| Ngasilake Kekuwatan | Kaku ing ngendi baja wiwit deform plastically. Penting kanggo beban-bearing. |
| Atose | Resistance kanggo indentation utawa abrasion (diukur ing HRC, HB, HV). |
| Kateguhan | Kemampuan kanggo nyerep energi lan deformasi tanpa fraktur (resistensi dampak). |
| Dhaptar | Kemampuan kanggo babagan tanpa rusak. Dituduhake dening elongation%. |
| Kekuwatan Kelelahan | Resistance kanggo siklus loading bola-bali. Penting kanggo gear, shaft, lan komponen liyane. |
2. Properti Fisik
| Property | Nilai khas utawa Range |
|---|---|
| Kapadhetan | ~7.85 g/cm³ |
| Titik lebur | ~1370–1510°C (gumantung isi paduan) |
| Thermal Conductivity | 45–60 W/m·K (kurang kanggo baja paduan) |
| Konduktivitas Listrik | Miskin (logam resistif) |
| Ekspansi Termal | ~11–13 µm/m·°C (beda-beda miturut kelas) |
3. Komposisi Kimia (Jinis Dasar)
| Tipe Baja | Unsur Alloy Utama | Cathetan |
|---|---|---|
| Karbon Baja | Besi + Karbon (nganti 2%) | Paling umum. Digolongake minangka kurang (≤0.3%), medium (0.3-0.6%), lan karbon dhuwur (0.6-1%). |
| Karet Baja | Cr, Ni, Mo, Mn, V, lsp. | Meningkat sifat mekanik lan tahan panas. |
| Steel | Cr ≥ 10.5% | tahan korosi. Biji kaya 304, 316. |
| Alat baja | W, Mo, Cr, V, Co | Digunakake kanggo nglereni alat lan mati. Atose dhuwur & resistensi nyandhang. |
| Baja Marging | Ni, Mo, Co, Ti | Kekuwatan sing dhuwur banget, kurang karbon, digunakake ing aerospace. |
4. Perawatan Panas lan Efek
| proses | Result |
|---|---|
| Annealing | Softens baja, nambah daktilitas, lan nambah machinability. |
| Quenching | Baja hardens (utamane baja karbon dhuwur / paduan). |
| Tempering | Nyuda brittleness sawise quenching lan ngimbangi atose lan kateguhan. |
| Normalisasi | Refines struktur gandum, nambah kekuatan lan kateguhan. |
| Hardening Kasus | Mung hardens lumahing (karburizing, nitriding). Becik kanggo pindah lan shafts. |
Grade Steel umum lan panggunaan
| grade | Koleksi | Properti & Aplikasi |
|---|---|---|
| AISI 1018 | Low-karbon | Weldability apik, digunakake kanggo shafts lan bagean cahya-tugas. |
| AISI 1045 | Sedheng-karbon | Luwih kuwat tinimbang 1018, cocok kanggo gear, as, lan bolt. |
| SCM440 / 4140 | Baja campuran | Kekuwatan dhuwur, tahan nyandhang, digunakake ing piranti, gear, lan bagean struktural. |
| SKD 11 / D2 | Baja alat | Atose dhuwur lan resistensi nyandhang, digunakake ing alat mati lan nglereni. |
| SUS304 | stainless | SS non-magnetik, tahan korosi, tujuan umum. |
| SUS316 | stainless | Tahan korosi sing luwih apik (klorida), digunakake ing laut / kimia. |
Tips Pilihan
Gunakake baja karbon rendah kanggo welding lan mbentuk bagean.
Gunakake medium-karbon dhuwur or campuran baja kanggo komponen struktural lan beban.
Gunakake stainless steel kanggo resistance karat.
Gunakake baja alat ngendi resistance nyandhang lan atose penting.
Tansah nimbang negara perawatan panas - baja ing kondisi annealed tumindak banget beda saka kelas padha sing quenched lan tempered.
Tabel Perbandingan Kelas Baja
| Properti / Kelas | SCM440 (AISI 4140) | S45C (AISI 1045) | SUS304 (AISI 304) | SKD11 (D2 Tool Steel) | SUS316 |
|---|---|---|---|---|---|
| Koleksi | Karet Baja | Baja Karbon Sedang | Baja Tahan Karat Austenitik | Baja Alat Kerja Dingin | Baja Tahan Karat Austenitik |
| Karbon (C) | ~ 0.40% | ~ 0.45% | ≤ 0.08% | ~ 1.5% | ≤ 0.08% |
| Kromium (Cr) | ~ 1.0% | - | ~ 18% | ~ 12% | ~16–18% |
| Nikel (Ni) | - | - | ~ 8% | - | ~10–14% |
| Kekerasan (sawise HT) | 28–45 HRC | 20-30 HRC (sirep/tempered) | ~90–95 HRB (anil) | Nganti 60 HRC (sawise hardening) | ~90 HRB (anil) |
| Kekuatan tarik | 850–1000 MPa (HT) | 600–800 MPa (HT) | ~520 MPa | ~1900 MPa (HT) | ~500 MPa |
| Kemampuan | Fair | Good | banget | Apil | banget |
| Kemampuan | Good | Good | Fair | Miskin – Adil | Fair |
| Resistance Korosi | kurang | kurang | High | kurang | Dhuwur banget (kelas laut) |
| Aplikasi khusus | Gir, poros, baut, mati | Poros, pin, gir | Tangki kelas pangan, pipa | Punch, mati, lan alat mbentuk kadhemen | Kelautan, kimia, farmasi |
Ringkesan miturut Use Case
SCM440 (4140): Baja kanthi kekuatan dhuwur sing apik kanggo roda gigi, poros, lan bagean otomotif - ngimbangi kekuatan, kateguhan, lan hardenability.
S45C (1045): Ekonomis, cocok kanggo bagean mekanik umum; ora hardenable minangka SCM440.
SUS304: Aman pangan, tahan karat; becik kanggo lingkungan sing rawan korosi njero ruangan.
SUS316: Luwih apik kanggo sugih klorida or lingkungan segara, kayata mesin pesisir utawa tank kimia.
SKD 11 (D2): Banget hard lan nyandhang-tahan; ora bisa dilas; digunakake kanggo dies lan nglereni industri.