Services - Heat Treatment Services

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Heat treatment is one of the most critical stages in manufacturing of rotary and fixed equipment in oil, gas and petrochemical industries. In general, it includes heating and cooling the metal equipment to achieve desired properties. The main reasons why heat treatment is required, include:

  • Relieving stress and tension caused by fabrication and welding operations
  • Modification of size and structure of metals
  • Creating a smooth metal surface, thereby increasing the reliability of the surface tensile strength of the metal in contact with the fluid
  • Improving steel properties in order to make it possible to replace the more expensive steel types with the cheaper types and consequently increasing the economic efficiency
  • Increasing absorption of the impact energy of steel
  • Improving the cutting properties of the tool steels
  • Improving electrical properties
  • Modification or improving magnetic properties 

The requirement for heat treatment is primarily specified by codes and standards on one hand and with regard to the application of the equipment and the type of services they are ought to provide on the other hand. Heat treatment can be conducted through different methods.

MFS is capable of providing the following heat treatment methods:

1.      Heat treatment using stationary furnace

2.      Heat treatment using mobile furnace

3.      Heat treatment internal firing

4.      Topical heat treatment

Heat Treatment Using Stationary Furnace

After completion of design, simulation of the furnace performance with aid of computing simulation software and evaluation of operation of the furnace (to find the best and most efficient arrangement of burners, thermocouples and dampers), MFS heat treatment furnace was fabricated with the following specifications.

Specifications of MFS stationary furnace

  • Applicable dimensions 20×9×9 meters.
  • Applicable for both complete and topical heat treatment operations
  • Capacity to handle a single 200,000 kg piece without limitation in thickness
  • Heating up the pieces up to 1200 0C
  • Thermal capacity 12,000,000 kcal/h with high velocity burners
  • Fully automatic control system
  • Dual fuel including LPG and CNG
  • Transporting pieces inside the furnace with railed trolley
  • Insulation with ceramic blanket

Advantages of MFS furnace

  • Utilizing years of experience in MFS and taking advantage of the capabilities of specialized operators and engineers
  • One of the largest and most modern heat treatment furnace in Iran
  • Working with both CNG and LPG, reducing the production of environmental pollutants.
  • Reducing the risk of damage to sensitive components used in sour service, caused by contaminants in fuel
  • Increasing energy efficiency due to minimized waste of energy
  • Amongst the major causes of damage and distortion  in components, temperature difference in different parts of the furnace can be noted. For this reason ASME standard allows 46°C temperature difference. Using an exclusive design, despite affording higher expenses, MFS has reduced temperature difference to 8°C
  • Utilizing high velocity burners to enhance air and fuel mixing and combustion and also to create thermal integrity in furnace area
  • Ability to provide continuous graphs and reports at any stage of the operation
  • Precise control of the components and furnace temperature using PLC control system with the ability to control burners, fuel gas and air inlet vanes and flue gas outlet from furnace stacks
  • Using 250mm ceramic blanket as insulation in order to minimize heat loss and reach thermal integrity in furnace area
  • A removable door, adjustable to size of different pieces, for hazardous area classification zone 4.
  • Ability to conduct heat treatment on components which are lengthier than furnace

Heat Treatment Using Mobile Furnace

Another service of the company is performing heat treatment using mobile furnace. In a way that first all sides of the component is insulated and covered by temporary structures in an allowable distance, then the burners which are located at regular intervals from the component will heat up the component indirectly. The advantages of this method include the possibility to assemble and dismantle the furnace promptly and that it does not require large separate spaces .For this method, MFS has mobile control panels which can be located around the component enabling the operator to control the operation. Component will heat up the component indirectly. The advantages of this method include the possibility to assemble and dismantle the furnace promptly and that it does not require large separate spaces. For this method, MFS has mobile control panels which can be located around the component enabling the operator to control the operation.

Internal Firing Method

MFS also offers Internal Firing as another method of heat treatment. Instead of moving the component to stationary furnace or even providing mobile furnace, it is heated up inside out through combustion gases and by transferring the hot fluid flow to the nozzles located on the component. This method is basically used for Post Weld Heat Treatment and Refractory Drying. It is mainly conducted on pieces which are large in size and weight and costly to move. It should be noted that this method is not recommended for components with internals. In this method heating is done through combustion burners and temperature control is done through thermocouples attached to the body of the component. It is important to stay alert of the rate of heat increase during internal firing operation to prevent probable damages which are caused by sectional overheating.

Topical Heat Treatment

One of the most common heat treatment methods for stress relieving, pre-heat Treatment, annealing and PWHT is Topical Heat Treatment, which can be done through two different techniques, namely Inductive and resistance. MFS applies Resistance heat treatment using flexible ceramic thermal elements. These elements consist of nickel chrome wires coated with alumina ceramic and are directly attached to the component. Temperature control is done by k-type thermocouples which are placed between the elements and are connected to thermo regulator and recording device. Inductive and resistance topical heat treatment are mainly used for heating the peripheral weld lines, small components and field activities on storage Tanks and components which are hard to move.

MFS applicable Heat Treatment Techniques

1. Post weld Heat Treatment

2. Annealing

Annealing is a thermal operation cycle which can improve the ductility properties of a component. After forming processes like rolling, extruding, forging etc., ductility of component deteriorates to some extent; in this situation annealing can be used to modify the component’s micro structure improving its dynamic properties. During this process, firstly according to the related codes of standards the component is exposed to temperatures higher than Austenite Temperature for a few times. Then based on the material type, annealing is applied in open air or even through quenching in water or cold oil or in furnace to improve its mechanical and structural properties.

3. Normalizing

Normalizing is a heat treatment technique which is mainly applicable for ferrous metal parts. In addition to operation temperature this technique also differs from annealing in cooling rate, which is done by air in normalizing.

The main objective of normalizing is to eliminate internal stresses caused by operations like topical heating of the welded part, casting, forging, forming and machining.

4. Stress Relieving

5. Quench& Tempered

Technical and Engineering Capabilities

Mechanical and process equipment for oil, gas, petrochemical, and power plant industries, MFS recognized the necessity for an exclusive heat treatment furnace for large scale industries to be accountable to the requirements of clients in the above mentioned industries. Finally in 2011, MFS fabricated its furnace in accordance with market requirements.

MFS takes advantage of a knowledgeable and experienced engineering team with high proficiency. During numerous projects, MFS has been responsible for preparing the instructions and procedures for heat treatment and stress relieving and is completely acquainted with the standards, Project specifications and client requirements. Consequently having a state of the art furnace alongside highly qualified engineering staff, MFS is now capable of conducting heat treatment in full compliance with ASME sec VIII UCS 56. We have trained our operating and inspection staff in a way that after completing a heat treatment operation, they provide our clients with a report including charts and curves of different stages of operation in accordance with standard principles. If required, they are also capable of measuring hardness, the amount of ferrite and any other requested parameters using calibrated measuring tools under the direct supervision of our clients.