Welded Flash Controlled, High Strength (690 MPa Tensile Strength), Low Alloy Steel Hydraulic Tubing, Stress Relieved, Annealed for Bending, Double Flaring, Cold Forming, and Brazing

2019 ◽  
Author(s):  
Author(s):  
Patricio Gustavo Riofrío ◽  
Carlos Alexandre Capela ◽  
José AM Ferreira ◽  
Amilcar Ramalho

High strength low alloy steels subjected to the thermomechanical control process present excellent strength–toughness combination, high strength/weight ratio, and weldability. Therefore, they are widely used in structural components, such as pressure vessels, oil/gas transportation pipes, lifting equipment, vehicles, shipbuilding and offshore industries, and in the automotive industry where low thickness (0.8–3 mm thickness) is of great importance. Usually, these steels are welded by conventional gas metal arc welding, which creates wide heat-affected zones, large residual stresses, and distortion in the welded parts. Laser welding is nowadays an alternative process to weld high strength low alloy steel parts due to its advantages. The aim of this work is to understand the effect of process parameters on defects, weld bead geometry, microstructure, and mechanical properties, namely hardness and tensile strength. We identify the main laser welding parameters and their influence on the weld bead geometry and defects, for a 3 mm thick high strength low alloy steel welded under a maximum power of 2 kW. A cross section of the weld seam was optimized achieving a good geometry without porosity. The threshold value of the heat input to achieve complete penetration was determined for different focus diameters. The microstructure, size, and hardness of the heat-affected zone and of the fusion zone are strongly influenced by the heat input. The values of the tensile strength achieved in butt welds were close to the base metal by an appropriate selection of the laser welding parameters and the heat input.


2012 ◽  
Vol 217-219 ◽  
pp. 467-470
Author(s):  
Xiao Hang Liu ◽  
Wen Jing Yuan ◽  
Hao Bin Tian ◽  
Fa Xi Diao

The mechanical properties and microstructure of the high strength low alloy HC340LA were obtained with different strain rate. The research shows that the better plasticity, higher tensile strength and yield ratio can be found in high speed tensile state than in quasi-static tension. The plasticity and tensile strength decrease with the increasing of the strain rate during the high speed tension. With the increasing of the strain rate, the grain size of the ferrite decreases and its distribution is uneven, and the grain boundaries increases. The HSLA steel HC340LA submit to obvious Ductile Frecture mechanism. The size of the dimples is more uniform, bigger and deeper with the strain rate 50 s-1 than with the strain rate 200 s-1. Therefore, the higher strain rate with over strain rate 50 s-1 has less Superscript textcontribution to the improvement of plasticity of the HSLA steel HC340LA.


Alloy Digest ◽  
2007 ◽  
Vol 56 (1) ◽  

Abstract The high strength of Tenform XF450, a hot-rolled high-strength low-alloy steel, allows the user to increase the strength of a finished component or to reduce the thickness. The steel is used in the construction and the automotive industries. This datasheet provides information on composition, physical properties, tensile properties. and bend strength. It also includes information on forming. Filing Code: CS-148. Producer or source: Hille & Mueller, USA Inc. See also Alloy Digest CS-173, November 2012.


Alloy Digest ◽  
1993 ◽  
Vol 42 (2) ◽  

Abstract LESCALLOY 300M VAC ARC is a low-alloy steel with an excellent combination of high hardenability and high strength coupled with good ductility and good toughness. Its tensile strength ranges from 280,000 to 300,000 psi. It is produced by the vacuum consumable electrode melting process to provide optimum cleanliness and preferred ingot structure. Its applications include aircraft components, pressure vessels and fasteners. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-321. Producer or source: Latrobe Steel Company. Originally published March 1976, revised February 1993.


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