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Heat treatment is an important part of the forging process. The heat treatment condition has a direct effect on the mechanical properties, hardness and micro structure of the final product.
At Eternal Heavy Industry, we provide heat treatment mainly for stainless forging, alloy forging and other custom forging products. The process is selected according to the material grade, forging size, section thickness and customer requirements.
Our heat treatment equipment supports temperatures up to 1300°C, covering a wide range of heat treatment processes.
Heat Treatment Capabilities
Our main heat treatment processes include:
Solution Annealing
Annealing
Normalizing
Quenching
Tempering
Quenching & Tempering (Q&T)
Stress Relieving
Induction Hardening (Upon Request)
The treatment is selected according to the material grade, forging dimensions, drawing requirements and applicable standard.
We mainly heat treatstainless steel and alloy steel forgings.
Typical materials include:
304 / 304L
316 / 316L
321 / 347
17-4PH
Duplex Stainless Steel
42CrMo / 42CrMo4
AISI 4140
AISI 4340
4130 / 4145
18CrNiMo7-6
H13 (Hot Work Tool Steel)
Other stainless and alloy steels according to customer requirements
For each custom forging, the heat treatment schedule is prepared according to the actual material and part size.
Solution Annealing
Solution annealing is widely used for stainless forgings, particularly austenitic and duplex stainless steels.
The forging is heated to the specified temperature, held for the required time and then rapidly cooled.
The process is used to obtain the required metallurgical condition and, where specified, maintain corrosion resistance and mechanical properties.
Annealing
Annealing is commonly used for alloy steel forgings where lower hardness and better machinability are required.
The forging is heated and held at the specified temperature, followed by controlled furnace cooling.
It is also used as a preparation condition for machining or subsequent heat treatment.
Normalizing
Normalizing is commonly used for carbon steel and alloy steel forgings.
The forging is heated above the required transformation temperature and held to obtain a uniform structure, then cooled in air.
Normalizing is often used before machining or subsequent quenching and tempering.
Quenching
Quenching is commonly used for alloy forgings where higher strength and hardness are required.
After heating and soaking, the forging is rapidly cooled using an appropriate medium such as oil, water, polymer or air.
For large forgings, cooling rate and temperature uniformity need to be controlled carefully to minimize distortion and residual stress.
Tempering
Tempering is normally carried out after quenching.
The forging is reheated to a specified temperature and held for the required time before cooling.
The tempering temperature is selected according to the required hardness, strength and toughness.
Tempering is commonly used together with quenching for alloy steel forgings.
Quenching & Tempering (Q&T)
Quenching and tempering is a common heat treatment condition for alloy steel forgings.
The forging is first heated and quenched to obtain the required hardened structure, followed by tempering at a controlled temperature.
The Q&T process provides a balance of strength, hardness and toughness and is widely used for forged shafts, hydraulic components, heavy equipment parts and other high-strength forgings.
Stress Relieving
Stress relieving is used to reduce residual stress generated during forging, rough machining or other manufacturing operations.
It is particularly useful for large custom forgings and components requiring extensive machining.
The forging is heated to a controlled temperature, held for the required time and then cooled under controlled conditions.
Induction Hardening (Upon Request)
Induction hardening is used when higher surface hardness and wear resistance are required on selected areas of a forging.
The required surface is rapidly heated by electromagnetic induction and then quenched.
The process can be used for selected alloy steel forgings, such as shafts and other components where localized surface hardening is required.
Induction hardening is available upon request, subject to the material grade, component geometry and technical requirements.
Heat Treatment Control
Main parameters include:
Heat treatment parameters are controlled according to the approved process and material specification.
Main parameters include:
Heating temperature
Soaking temperature
Soaking time
Furnace temperature
Cooling method
Quenching parameters
Tempering temperature and time
Heat treatment records can be supplied together with the required inspection documents.
Inspection After Heat Treatment
After heat treatment, the forgings can be inspected according to the drawing, material standard and customer requirements.
Available inspections include:
Hardness Testing
Tensile Testing
Impact Testing
Metallographic Examination
Ultrasonic Testing (UT)
Magnetic Particle Testing (MT)
Dimensional Inspection
For stainless forging and alloy forging, the inspection requirements are agreed before production and recorded as part of the manufacturing documentation.
Heat Treatment for Large Forgings
Large forgings require more attention to heating, soaking and cooling because of their section size and weight.
ETERNAL has experience with heat treatment of large custom forging components, including forged shafts, rings, hydraulic cylinder components, valve components, trunnions and other heavy forgings.
The heat treatment schedule is developed according to the material, maximum section thickness and required mechanical properties.
From Forging to Heat Treatment
ETERNAL operates an integrated production process:
Raw Material → Forging → Heat Treatment → Rough Machining → Final Machining → Inspection
Having forging and heat treatment in the same production system allows our team to coordinate the two processes directly.
This is particularly useful for custom forging projects where material requirements, heat treatment and machining tolerances need to be considered together.
Applications
Our heat-treated forgings are supplied for:
Oil & Gas
Petrochemical
Power Generation
Marine & Offshore
Mining
Heavy Equipment
Hydraulic Equipment
Steel Industry
General Industrial Equipment
Why ETERNAL
ETERNAL is a manufacturer of custom forgings, stainless forgings and alloy forgings with in-house forging, heat treatment, machining and inspection.
Our production covers both standard material grades and customer-specific requirements.
For each project, we work from the drawing and material specification to determine the appropriate forging and heat treatment process.
Our quality system is supported by ISO 9001, ISO 14001 and PED certification.
For customers who need a complete manufacturing solution rather than heat treatment alone, ETERNAL can provide:
Forging + Heat Treatment + Machining + Inspection
Heat Treatment for Your Forging
Have a drawing, material specification or heat treatment requirement?
Send it to our engineering team. We can review the material, dimensions and required properties and provide a suitable production process and quotation.
