Method of manufacturing thick, high-strength steel pipe for low temperature service
US4020312A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 21, 1975 |
| Grant date | Apr 26, 1977 |
| Priority date | — |
| Expiry date | Nov 21, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K35/3053
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of manufacturing a thick, high-strength steel pipe for low temperature service comprising the steps of forming into tubular shape a steel plate having a thickness of over 12 mm and a specific composition, of which the C.sub.eq value is adjusted to less than 0.50, when the Mn content is less than 1.0 % whereas the C.sub.eq value is adjusted to less than 0.45 when the Mn content is over 1.0 % and less than 2.0 %, and nextly of welding said tube form at high speeds and high efficiency by the process of single electrode or multiple electrode large-current gas-shielded arc welding with one pass per electrode on each side of the seam at a specific condition, each electrode preferably consisting of a solid wire essentially containing less than 0.3 % Ti with or without the addition of less than 0.01 % B, and said steel pipe having, in its as-welded condition, mechanical properties such that the yield point of the base metal portion is over 60,000 psi and the weld zone has a maximum hardness of less than Hv10-280 and a Charpy test absorbed energy of over 7 Kg.m at -10.degree. F. Even when the C.sub.eq value of said steel plate is less than 0.65, a thick, high-strength steel pipe fo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.