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Abstract: The influence rule of air environment pressure on all position primary welding parameters and welding quality under hyperbaric environment is investigated. The investigation shows that the environment pressure has some effect on weld penetration. Primary welding current of downhand welding decreases linearly with the ambient pressure increasing from 0.1 MPa to 0.7 MPa; Primary welding current of overhead position welding and upward welding in the inclined position decreases greatly with the ambient pressure increasing from 0.1 MPa to 0.3 MPa and then changes little afterwards. Primary welding current of downward welding in the incline presents lenitive descent trend with the ambient pressure increasing from 0.1 MPa to 0.7 MPa. Ambient pressure has great affection on mechanical property of welding joint, tensile strength and impact toughness of joint decrease with the ambient pressure increasing, while the hardness of HAZ and welding seam increase.
Key words: High-pressure TIG All-position
One side welding with back formation Mechanical property
CLC No:
TG457.11
国家高技术研究发展计划资助项目(863 计划, 2002AA602012-3). Received 20061108,
received
in
revised
form
20070606
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