Post Weld Heat Treatment
The secret to a long refractory life is a professional dry-out using THT Service's high velocity gas burners to ensure that every inch of your refractory / furnaces is heated uniformally and under strict control. Dry-outs are designed to:
Completely remove both free and chemically held water to minimise spalling and cracking.
Prevent the formation of thermal stresses that could weaken the refractory.
Assure cross-sectional ceramic bonding for exceptional refractory life.
Prevent separation of refractory from surface.
Eliminates thermal spiking.
Total Heat Treatment Services' technicians are well trained in this process and will complete the job to the clients' specifications and time constraints.
Pre Heating Service
Post Weld Heat Treatment (PWHT) is the heating of metal to a relatively high temperature shortly after welding, and maintaining that temperature for a specific period of time.
The purpose is to:
Reduce Internal stresses
Improve resistance to corosion and caustic embrittlement
More ductility / elasticity in the weld metal and the lowering of hardness
Improve machining stability and strength of the metal
ELECTRIC and GAS FURNACES
THT Services' facilities include fully equipped furnaces capable of heating items up to 6.8 metres.
The workshop also has various sizes of electric furnaces suitable for smaller items. For items unable to be transported to our workshop due to their size and/or other constraints we can design and build temporary furnaces for our clients on-site.
THT Services' technicians are experienced in building paneled furnaces as its a very common procedure requested by our clients.
Pre Heating is a very effective means of preventing weld metal or base metal cracking. It is the application of heat to the base metal prior to welding or cutting operation. It does not change the properties of the steel but it is advisable under certain conditions to keep the metal soft ensuring even expansion to eliminate undesirable stresses. Pre Heating during welding retards the cooling effect thus preventing formulation of an under bead crack. Pre Heating dries off moisture and increases the diffusion rate of hydrogen and facilitates its removal from a welded joint.
Throughout the world there is a growing realisation that more thought has to be given to pre heat when welding low alloy steels, it has been proven that controlled electrical pre heat is the best insurance tor making a sound weld.