Development of Laminar Plasma Shielded HF-ERW Process: Advanced Welding Process of HF-ERW 3

2012 ◽  
Author(s):  
Hideki Hamatani ◽  
Funinori Watanabe ◽  
Nobuo Mizuhashi ◽  
Sunao Takeuchi ◽  
Yoshiaki Hirota ◽  
...  
Keyword(s):  
High Temperature ◽  
Welding Process ◽  
Air Entrainment ◽  
Plasma Jets ◽  
Control Technique ◽  
Monitoring Methods ◽  
Line Pipe ◽  
Temperature State ◽  
Weld Area ◽  
Cold Gas

High frequency - electric resistance welded (HF-ERW) pipe has been successfully used for many years for a number of applications. The benefits of HF-ERW pipe are considerable, including a higher dimensional tolerance and lower prices than seamless pipe and UO pipe. The conventional weld seam produced by HF-ERW, however, often has a relatively low toughness. We have developed an automatic heat input control technique based on ERW phenomena that relies on optical and electrical monitoring methods and has been shown to result in a significant improvement in the toughness. Shielding of the weld area must also be considered as a key factor in the formation of a sound weld. It has been shown that an inert cold gas (e.g., at room temperature) shielding technique is effective for maintaining a stable low oxygen state in the weld area that inhibits the formation of penetrator, a pancake oxide inclusions. Compared to the cold gas shielding technique, high temperature gas shielding, due to its higher kinetic viscosity coefficient, should make it easier to sustain a higher laminar flow, thus leading to a rather low air entrainment in the shielding gas. In addition, plasma is a much higher temperature state (∼6000 K), and the dissociated gases can react with the entrained oxygen; plasma jets should, therefore, enhance the overall shielding effects. Moreover, oxides on the strip edges can be expected to melt and/or be reduced by the high temperature plasma jets. Nippon Steel has developed a plasma torch that can generate a long and wide laminar argon – nitrogen – (hydrogen) jet. This paper describes the results obtained from our investigation of the effects of a plasma jet shield on the weld area of high strength line pipe with a yield strength grade of X65. Preliminary attempts in applying this novel shielding technique has been found, as expected, to demonstrate extremely low numbers of weld defects and a good low temperature toughness of the HF-ERW seam.

scholarly journals Structure Analysis and Design of Automobile plastic clutch pump body based on friction welding

2020 ◽  
Vol 316 ◽  
pp. 02001
Author(s):  
Jing Sheng ◽  
Aamir Sohail ◽  
Mengguang Wang ◽  
Zhimin Wang
Keyword(s):  
High Temperature ◽  
Structural Design ◽  
Friction Welding ◽  
Room Temperature ◽  
Welding Process ◽  
Structure Type ◽  
Mechanical Analysis ◽  
Analysis And Design ◽  
Technical Requirements ◽  
Design Requirements

In order to realize the need for lightweight automobiles through replacing steel with plastics, the research and development of the plastic clutch pump body based on the friction welding was carried out. For the clutch pump body connected by friction welding process between the upper pump body and the lower pump body, the technical requirements of pressure 14 MPa and durability (high temperature 7.0 × 104 times, room temperature 7.0 × 105) are required. The structure type of the upper and lower pump bodies of the end face welding type was proposed. Through the static analysis of the pump body and weld and the mechanical analysis under the working condition, the structure of the clutch pump body (upper and lower pump body) was determined. According to the established welding process, the pressure of the clutch pump body is more than 15 MPa, and the number of high-temperature durable circulation and the number of room temperature durable circulation also reached 7.2×104 and 7.3×105 times respectively. The results show that the structural design of a clutch pump body meets the design requirements.

scholarly journals Control Technique of Solidus Temperature on Gold Base Solder for SiC Devices with High Temperature Operation

2014 ◽  
Vol 3 (4) ◽  
pp. 205-211 ◽  
Author(s):  
Hiroki TAKAHASHI ◽  
Hiroki TAKAHASHI ◽  
Yoshinori MURAKAMI ◽  
Yoshinori MURAKAMI ◽  
Takeshi ANZAI ◽  
...  
Keyword(s):  
High Temperature ◽  
Solidus Temperature ◽  
Control Technique ◽  
High Temperature Operation

scholarly journals A Single Cycle Inverter Welding Power Control System

2012 ◽  
Vol 4 ◽  
pp. 101-105
Author(s):  
Peng Fei Huang ◽  
Yang Yang Lu ◽  
Shao Jun Bai ◽  
Zhen Yang Lu
Keyword(s):  
Control System ◽  
Power Control ◽  
Short Circuit ◽  
Welding Process ◽  
Control Technique ◽  
Magnetic Saturation ◽  
Single Cycle ◽  
Waveform Control ◽  
Short Time ◽  
Saturation Dose

Single cycle control technique is applied in the field of welding power which makes waveform control in the various stages of arc and circuit in the welding process respectively based on the characteristics of the welding process. A new welding power control has been put forward which is able to adjust the grid voltage disturbance in a very short time. We choose dual single-ended forward topology as the main circuit and make flux reset for the transformer in each cycle to ensure that the transformer magnetic saturation dose not occur, meanwhile, controlling the condition of arcing and short circuit respectively to achieve a better welding effect.

Issues in Welding of HSLA Steels

2011 ◽  
Vol 365 ◽  
pp. 44-49 ◽  
Author(s):  
Sandeep Jindal ◽  
Rahul Chhibber ◽  
N.P. Mehta
Keyword(s):  
Structural Integrity ◽  
Hsla Steel ◽  
Weight Ratio ◽  
Welding Process ◽  
Pressure Vessels ◽  
Carbon Steels ◽  
Low Carbon ◽  
Line Pipe ◽  
Hsla Steels ◽  
Selection Of

The application of High Strength Low Alloy (HSLA) steels has expanded to almost all fields viz. automobile industry, ship building, line pipe, pressure vessels, building construction, bridges, storage tanks. HSLA steels were developed primarily for the automotive industry to replace low-carbon steels in order to improve the strength-to-weight ratio and meet the need for higher-strength materials. Due to higher-strength and added excellent toughness and formability, demand for HSLA steel is increasing globally. With the increase of demand; other issues like the selection of filler grade and selection of suitable welding process for the joining of these steels have become very significant. This paper discusses the various issues regarding selection of suitable grade and selection of suitable welding process for joining of HSLA steels and issues concerning the structural integrity of HSLA steel welds.

Experimental Study on the Single-Sided Double-Point Resistance Welding of Bus Roof Skin

2014 ◽  
Vol 680 ◽  
pp. 97-101
Author(s):  
Hai Bin Huang ◽  
Jian Chun Liu ◽  
Xiao Long Ke ◽  
Xiao Hui Lin
Keyword(s):  
Double Point ◽  
Low Carbon Steel ◽  
Welding Process ◽  
Welding Current ◽  
Resistance Welding ◽  
Galvanized Steel ◽  
Low Carbon ◽  
Support Mechanism ◽  
Experiment Platform ◽  
Weld Area

In order to weld the skin and skeleton of bus roof, it analysis the welding process of bus Outer Roof-panels , and specify the weld area and solder joint distance of outer roof-panel firstly , then built a single-sided double-point resistance welding experiment platform for bus outer roof-panels, the platform consists of guide、gantry、gantry moving mechanism、 pneumatic torch、electrode support mechanism、transformers、torch lateral movement organizations and torch longitudinal movement phenomenon . it set the unevenness of the skin and the skeleton as 1mm, single-sided double-point resistance welding experiment was conducted on the welding experiment platform. The experimental results of welding area visual examination and tear experiments indicate that welding heat will penetrate the skeleton when the welding current is greater than 11.0KA;the welding Reliability of galvanized steel is better than low carbon steel.

Cold gas dynamic spraying of a high temperature Al alloy

2006 ◽  
Vol 201 (6) ◽  
pp. 2109-2116 ◽  
Author(s):  
L. Ajdelsztajn ◽  
A. Zúñiga ◽  
B. Jodoin ◽  
E.J. Lavernia
Keyword(s):  
High Temperature ◽  
Cold Gas Dynamic Spraying ◽  
Al Alloy ◽  
Gas Dynamic ◽  
Cold Gas

Tensile and Toughness Properties of Pipeline Girth Welds

2006 ◽  
Author(s):  
J. A. Gianetto ◽  
J. T. Bowker ◽  
R. Bouchard ◽  
D. V. Dorling ◽  
D. Horsley
Keyword(s):  
Weld Metal ◽  
Welding Process ◽  
Strain Curve ◽  
High Strength ◽  
Primary Objective ◽  
Stress Strain ◽  
Line Pipe ◽  
Arc Welding Process ◽  
Girth Welds ◽  
Metal Microstructure

The primary objective of this study was to develop a better understanding of all-weld-metal tensile testing using both round and strip tensile specimens in order to establish the variation of weld metal strength with respect to test specimen through-thickness position as well as the location around the circumference of a given girth weld. Results from a series of high strength pipeline girth welds have shown that there can be considerable differences in measured engineering 0.2% offset and 0.5% extension yield strengths using round and strip tensile specimens. To determine whether or not the specimen type influenced the observed stress-strain behaviour a series of tests were conducted on high strength X70, X80 and X100 line pipe steels and two double joint welds produced in X70 linepipe using a double-submerged-arc welding process. These results confirmed that the same form of stress-strain curve is obtained with both round and strip tensile specimens, although with the narrowest strip specimen slightly higher strengths were observed for the X70 and X100 linepipe steels. For the double joint welds the discontinuous stress-strain curves were observed for both the round and modified strip specimens. Tests conducted on the rolled X100 mechanized girth welds established that the round bar tensile specimens exhibited higher strength than the strip specimens. In addition, the trends for the split-strip specimens, which consistently exhibit lower strength for the specimen towards the OD and higher for the mid-thickness positioned specimen has also been confirmed. This further substantiates the through-thickness strength variation that has been observed in other X100 narrow gap welds. A second objective of this study was to provide an evaluation of the weld metal toughness and to characterize the weld metal microstructure for the series of mechanized girth welds examined.

Repair Weldability at Overlay/Base Metal Interface of Petroleum Pressure Vessel

2008 ◽  
Author(s):  
Rinzo Kayano ◽  
Hiroaki Mori ◽  
Kazutoshi Nishimoto
Keyword(s):  
High Temperature ◽  
Hydrogen Embrittlement ◽  
Hydrogen Content ◽  
Welding Process ◽  
Pressure Vessels ◽  
Cold Cracking ◽  
Diffusible Hydrogen ◽  
Repair Welding ◽  
Crack Susceptibility

In order to extend the life of petroleum pressure vessels operated in long term, it is needed to establish the reliable repair welding technique. Weld cold cracking sometimes occurred in long-term operated petroleum pressure vessels due to hydrogen embrittlement by thermal stress and diffusible hydrogen after repair welding. The cracking was caused by the hydrogen concentration at the base meal of 2.25Cr-1Mo steel/overlaying metal of austenitic stainless steels interface during the service with high temperature and hydrogen partial pressure. The tendency was accelerated by carbide precipitation at the interface due to the post weld heat treatment (PWHT) and the operation with high temperature. That is, the crack susceptibility at the interface became markedly higher owing to the hydrogen embrittlement with metallurgical degradation by thermal embrittlement. To make clear the effect of weld thermal cycles during repair welding on the hydrogen content and weld cold cracking at the interface in the structural material of petroleum pressure vessels, the crack susceptibility was estimated by y-groove weld cracking test with varying overlay thickness and hydrogen exposure conditions. In addition, the hydrogen distribution in the material was calculated by the theoretical analysis using the diffusion equation based on activity. The crack susceptibility was raised with increase in the hydrogen content at the interface. It was concluded that the cracking could be prevented by controlling the repair welding process to reduce the hydrogen content at the interface.

Entrainment of cold gas into thermal plasma jets

1991 ◽  
Vol 11 (4) ◽  
pp. 529-543 ◽  
Author(s):  
E. Pfender ◽  
J. Fincke ◽  
R. Spores
Keyword(s):  
Thermal Plasma ◽  
Plasma Jets ◽  
Thermal Plasma Jets ◽  
Cold Gas
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