Requirement of welds for the mass production of automotive body parts, the potential benefits such as increased stiffness due to electron beam welding leading to improved vehicle structural performance, smaller heat-affected zone
& less thermal distortion due to the use of electron beam, high-quality welding of complex components, and high speed automated welding process using electron beam welding are further fueling the growth of the industry.
Quality is key and there are stringent requirements on aspects such as burr formation, delamination, particle debris formation and heat-affected zone
. Single mode CW fibre lasers can be used very effectively for the cutting of bare foils, but may not be the best choice for the cutting of coated electrodes.
Nomenclature API = American Petroleum Institute ASME = American Society of Mechanical Engineers ASTM = American Society for Testing and Materials a = crack length C(T) = compact tension da/dV = fatigue crack growth rate [DELTA]K = stress intensity factor range FCGR = fatigue crack growth rate HAZ = heat-affected zone
HA-FCG = hydrogen-assisted fatigue crack growth GH = girth heat-affected zone
GW = girth weld N = number of cycles SH = seam heat-affected zone
SW = seam weld w = width of the specimen Keywords: fatigue crack growth rate; high-pressure hydrogen; hydrogen embrittlement; pipe steels; residual stress.
The structure, chemical composition as well as weld pool geometry and heat-affected zone
(HAZ) have huge influence on mechanical properties of the welded joints.
Laser cladding can provide a permanent structural repair and refurbishment of high-value components made of alloys that are generally considered unweldable, due to the small heat-affected zone
, rapid solidification, improved cleanness and lower dilution, as well as greater control over the depth of the heat-affected zone
The heat-affected zone
embraces the fusion zone and has the width of 100-250 [micro]m, which is marked between the red dash line and blue dash line.
Liu, "Interaction study of carbide precipitation and impurity segregation under temper embrittlement conditions in a coarse-grained heat-affected zone
in Q690 steel," Advanced Materials Research, vol.
This additive manufacturing process builds up and repairs the surface of the metal part without creating a heat-affected zone
that would occur during welding or high temperature thermal spray.
Underbead cracking or a lack of toughness in the heat-affected zone
is not usually encountered when welding carbon steel containing no more than 0.2% carbon and 1% manganese.
Adding garnet to the stream for abrasive waterjet, a process invented at Flow, slows the process somewhat, but increases accuracy, (as the stream thins and cuts become more precise), all with no heat-affected zone
or work-hardening on metal parts.
The main purpose of the rumbling action can be to stress-relieve case hardening in the heat-affected zone
(HAZ) around the component edges.
Ascent's traveling laser-welding robot minimizes the heat-affected zone
and does not introduce high thermal loads into the structure.