Title:
SOLDERING DEVICE
Document Type and Number:
Japanese Patent JP3311547
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To obtain welding excellent in elongation by setting an oxygen partial pressure of atmosphere in contact with fused slag to a specified value when welding a fire resistant steel for construction containing B of a specified quantity.
SOLUTION: Fire resistant steels 1, 2 for construction containing 0.00030.0025% B are welded with a non-consumable nozzle electroslag method. A welding space is formed along a backing plate 5 at the welding part of the fire resistant steels 1, 2. A nozzle 3 is inserted in the welding space, welding is executed with supplying/fusing a welding wire 4. The gas having an oxygen partial pressure higher than that of a gas pipe 7 is blown into the welding space and an oxygen partial pressure of atmosphere in contact with the fused slag 6 is set to ≥0.35. As the oxygen partial pressure of atmosphere is set higher, as a result, the oxygen partial pressure of fused slag is made higher, so oxidation of B is increased. In the case B content in the fire resistant steel is <0.0003%, hardening effect is not developed, in the case of >0.0025%, the hardenability is turned to excessive.
Inventors:
Toshio Takeda
Yougo Kaneko
Yougo Kaneko
Application Number:
JP19738995A
Publication Date:
August 05, 2002
Filing Date:
August 02, 1995
Export Citation:
Assignee:
Nippon Electric Heat Meter Co., Ltd.
International Classes:
B23K31/02; B23K1/08; B23K3/06; H05K3/34; (IPC1-7): B23K1/08; B23K31/02; H05K3/34
Domestic Patent References:
| JP6328239A | ||||
| JP8309519A | ||||
| JP7501657A |
Other References:
【文献】米国特許5409159(US,A)
Attorney, Agent or Firm:
Masataka Kobayashi