Looking throughout the history of manufacturing within the UK, the automotive industry has made up a large proportion of manufacturing output, a trend still seen today despite troubling economic times. Large car manufacturers like Mini, Honda and Toyota still continue to produce certain models from the UK, assisted by skilled and experienced welders. This has helped contribute to the 1,671,166 cars reported to have been manufactured in the UK in 2017, with 53.9% of these being exported within the European market. This massive demand requires both manufacturing and welding processes to be precise and efficient to help avoid unplanned downtime where production is paused. This article will discuss the different arc-welding processes used in automotive manufacturing and the difficulties faced within the automotive industry.
The automotive industry has received recent pressure to reduce CO2 emissions from automobiles, one solution to combat emissions is by reducing the overall body weight of cars. In order to achieve this, an increased effort has been made to use thinner steel sheets of 780-MPa class in the manufacturing of chassis and body parts. To produce chassis parts, arc-welding is typically favoured due to the ease of the process in producing a continuous join. This offers high strength and rigid joints in a variety of joint shapes, allowing the joining of pipes, brackets and other automotive accessories. This technique also allows for chassis parts to have weld joints that are highly resistant to fatigue and corrosion. Additional techniques are also used in an effort to reduce spatter and improve gap weldability.
The aim of a weld joint is to have a higher strength than that of the base metal, to achieve this in automotive welding, welding wires are used in the joining of high-strength steel sheets. When welding thin sheets, the arc-weld is usually completed in a single pass and the base metal will make up for 30-40% of the weld metal in typical conditions. Also, as the heat input when welding thin sheets is low, the cooling rate is high and the weld metal tends to harden. Due to this, high weld strength between high-strength steel sheets can be achieved regardless of the grade of welding wire used. Typically, as the class of welding wire increases, so does the strength of the weld, with 780 MPa welding wire producing the highest weld strength with all base metals.
When using arc-welding processes within automotive processes, welders are faced with a number of issues which can impact production and efficiency. One of the largest issues with automotive welding is poor fit, this can be caused from a number of reasons including distortion during welding or parts not being cut correctly. Poor fit can be extremely costly to manufacturers, increasing weld metal volume but also having a negative impact on the strength of the weld. Another issue with automotive welding is spatter, this is the production of droplets of metal and non-metallic materials during the welding process that can stick to the base material or any surrounding metallic materials. Leaving spatter on the base materials can help to increase the risk of corrosion, reducing the longevity of welds.
Orbital Fabrications is a leader in the welding industry providing a range of orbital welding, manual welding and other specialist welding services. Our team of highly skilled welders have years’ of experience delivering TIG welding and fabrication services to a range of sectors including projects within the medical, nuclear and automotive industries. In addition to offering fabrication engineering solutions for the past 25 years, Orbital Fabrications also offers machining services, turnkey design and helium leak testing.
After recent expansions to their facilities, Orbital Fabrications continues to invest in welding equipment and staff training to deliver industry-leading services. Orbital Fabrications also offers Class 6 and Class 5 cleanroom services from their St. Ives facility. Offering support for a range of in-house and on-site welding contracts, Orbital Fabrications remains one of the leading welding companies in the UK.
If you would like to find out more information about any of Orbital Fabrications’ services, call on 01480 464 066 or contact us here.