Ikki fazali-fazali titanium qotishma isitgich trubkasidagi alfa-fazaning hajm ulushi vodorod diffuziya koeffitsienti va gidridning kechikishi uchun chegara kuchlanishini qanday o'zgartiradi?
Xabar QOLDIRISH
Ikki-fazali titanium qotishmalarida (masalan, 5-sinf, Ti-6Al-4V) alfa-faza (HCP) va beta{10}}fazaning (BCC) hajm ulushi vodorod diffuziyasining harakatini aniqlaydi. Vodorod beta{12}}fazada (BCC tuzilishi) alfa fazaga qaraganda tezroq tarqaladi. Yuqori alfa-fazali hajm ulushi samarali vodorod diffuziya koeffitsientini pasaytiradi va kechiktirilgan gidrid yorilishi (DHC) uchun chegara kuchlanishini oshiradi. 5-darajali (taxminan 50-60% alfa) uchun diffuziya koeffitsienti oraliq va DHC chegara kuchlanishi 180-250 MPa.
Miqdoriy alfa-Faza ulushi va DHC qarshiligi
| Alfa{0}}faza hajmining ulushi (%) | Qotishma misoli | H diffuziya koeffitsienti (sm²/s, 25 daraja) | DHC chegara kuchlanishi (MPa) |
|---|---|---|---|
| 100 | 2-sinf (savdo sof) | 2 × 10⁻¹⁰ | 120–180 |
| 70 | 9-sinf (Ti-3Al-2,5V) | 5 × 10⁻¹⁰ | 160–220 |
| 50–60 | 5-sinf (Ti-6Al-4V) | 8 × 10⁻¹⁰ | 180–250 |
| 30–40 | Beta-C (Ti-35V-15Cr) | 2 × 10⁻⁹ | 200–280 |
| 0 | Beta-21S (Ti-15Mo-3Al-3Nb) | 5 × 10⁻⁹ | 250–350 |
Alfa{0}}faza fraksiyasining vodorod bardoshliligiga ta'siri
| Alfa fraksiyasi (%) | Maksimal ruxsat etilgan H<0.1 mm/year Crack Growth (ppm) | Nordon xizmati uchun tavsiya etiladi |
|---|---|---|
| 100 | 150–200 | Marginal |
| 70 | 200–300 | Qabul qilinadi |
| 50–60 | 300–400 | Yaxshi |
| 30–40 | 400–600 | Juda yaxshi |
| 0 | 600–1,000 | Ajoyib |
Nordon xizmati uchun qotishma tanlash bo'yicha qo'llanma
| H₂S qisman bosim (bar) | Tavsiya etilgan alfa fraksiyasi (%) | Tavsiya etilgan qotishma |
|---|---|---|
| <0.01 | Har qanday | 2-sinf |
| 0.01–0.05 | <70 | 9-sinf |
| 0.05–0.2 | <60 | 5-sinf |
| 0.2–0.5 | <40 | Beta-C |
| >0.5 | <20 | Beta-21S |
Muhandislik bo'yicha tavsiya
For hydrogen-rich sour service (H₂S partial pressure >0,1 bar), ikki{1}}fazali qotishmalarni quyi alfa-fazali hajm ulushi bilan belgilang (masalan, 5-darajali yoki Beta-C). Alfa{8}}fazali fraktsiyani nazorat qilish orqali muhandis DHC chegara kuchlanishini oshiradi va vodorod bardoshliligini yaxshilaydi.
