Heat Treating Specialties

ANNEALING (300 – 2250F)

The purpose for this treatment is to remove stresses or soften the material for improved mach inability or formability, alter the physical or mechanical properties or produce a defined structure.

Process Anneal: (500 – 1400F)

Low temperature anneal typically used for material (ferrous or nonferrous) that is going to be reworked via cold rolling or drawing. This type of anneal is also applied to material to improve formability for forming/bending operations with reduced risk of distortion associated with intercritical or full annealing.

Subcritical Anneal: (500 – 1400F)

Annealing process conducted at a temperature below the lower critical for ferrous material and below the full anneal temperature for nonferrous materials. Also referred to as process annealing. This anneal is used to restore ductility to the material for subsequent cold-working/forming operations.

Intercritical Anneal: (1335 – 1600F)

Annealing process typically applied to ferrous material heated to and held at a temperature between the upper and lower critical temperatures for ferrous materials.

Intermediate Anneal: (500 – 1400F)

Recovery Anneal: (300 – 1000F)

Annealing process typically applied to cold-worked material to reduce residual stresses and recover ductility in the material. Temperatures used are below those required for recrystallization or new grain formation.

Recrystallization Anneal: (330 – 1450F)

Annealing process typically applied to cold-worked metal to produce a new grain structure without going through a phase change in the case of ferrous materials.

Isothermal Anneal: (1300 – 1650F)

Annealing process for ferrous materials partially of fully austenitize followed by slow cooling to below the lower critical temperature and held for transformation to a soft, coarse pearlite (aggregate of ferrite and iron carbide).

Spheroidize Anneal: (1200 – 1400F)

Annealing process for ferrous materials (medium to high carbon, low alloy steel) to produce a structure of globular carbides in a ferritic matrix for improved formability and machining.

Full Anneal: (650 – 1650F)

Annealing process for ferrous and nonferrous materials for produce the softest, stress-free structure for improved mach inability, cold-workability, mechanical or electrical properties, and dimensional stability. For ferrous materials, heat to above the upper critical transformation temperature and hold to obtain full austenitization, and slow cool to ambient temperature. For nonferrous materials, heat at the specified alloy anneal temperature, hold for a specified time, and furnace cool to ambient temperature.

Solution Anneal: (900 – 2250F)

Annealing process for ferrous and nonferrous materials to produce a solid solution of alloy elements for age-hardening or precipitation-hardening, or improved machining, formability, and/or corrosion resistance. This process is comprised of heating to a specified temperature, holding for a specified time, and cooling rapidly to ambient temperature. This process is typically the precursor to an age-hardening operation for precipitation – hardenable alloys.

TEMPERING (350F – 1250F)

his treatment follows a quenching or air cooling operation. Tempering is generally considered effective in relieving stresses induced by quenching in addition to lowering hardness to within a specified range, or meeting certain mechanical property requirements.

STRESS RELIEVING: (300 – 1400F)

Thermal Stress Relieving is generally applied to metallic materials that have been cold-worked, formed, machined, flame-cut, or weld-fabricated to reduce residual stresses for dimensional stability or reduced risk of premature failure in service.

ASME Section I: (900 – 1300F)

Stress relieve/Post-Weld Heat Treat in accordance with ASME Section I, PW-39 for carbon steel weldments.

ASME Section VIII: (900 – 1300F)

Stress relieve/Post-Weld Heat Treat in accordance with ASME Section VIII, UCS-56 for carbon steel weldments.

AWS D1.1: (900 – 1200F)

Stress relieve/Post-Weld Heat Treat in accordance with AWS D1.1, 5.8. for carbon steel or quench and tempered weldments.

Westinghouse 83030QA: (1175F 25F)

Westinghouse approved stress relieve procedure for carbon steel welded structures.

General Electric P8A-AG1, P10G-AL-0003 & -0004: (1125 – 1275F, 1125 – 1200F, and 1250 – 1300F)

General Electric approved stress relieve procedures for carbon steel.

Standard Stress Relieve: (1100 – 1200F)

Typically applied to ferrous materials to reduce residual stresses for improved dimensional stability or reduced risk of premature failure in service.

Low Temperature Stress Relieve: (325 – 775F)

Typically applied to Stainless Steel and Aluminum Welded Fabrications to reduce residual stresses with little or no effect of the corrosion resistance and/or mechanical properties.

NORMALIZING (1600 – 1800F)

Normalizing is generally applied to ferrous materials to enhance the mechanical properties of the material by refining the microstructure. This treatment will in some instances improve mach inability and machine finish. This treatment is sometimes used as precursor to subsequent surface hardening to improve response to hardening, or to provide desirable base substrate hardness.

HARDENING (2250F max)

Hardening via water-quench, oil-quench, forced- or still-air quench, or aging results in improved mechanical properties, hardness, and toughness of the alloy material.

Water Quench (Up to 2250F) & Tempering (350 – 1200F):

This process is applied to water-hardening medium carbon and low carbon alloy grades of steel for improved strength, hardness, and toughness in light to moderate sections sizes.

Oil Quench (Up to 2250F) & Tempering (350 – 1200F):

This process is applied to oil-hardening medium-to-high carbon and medium-to-high carbon alloy grades of steel for improved strength, hardness, and toughness in moderate to heavy section sizes.

Forced-Air Quench (Up to 2250F) & tempering (350 – 1200F):

This process is applied to medium carbon low alloy grades of steel for improved strength, hardness, and toughness with reduced risk of distortion.

Still-Air Quench (Up to 2250F) & Temper (350 – 1200F):

This process is applied to air-hardening grades of steel for improved strength, hardness, and toughness with reduced risk of distortion.

Age Hardening (300 – 1400F):

This process is applied to age-hardenable, or precipitation – hardenable ferrous and nonferrous alloys for improved strength, hardness, and toughness with reduced risk of distortion.

QUENCHING (2250F max)

Quenching is an integral part of hardening via water-quench, oil-quench, forced- or still-air quench, solution anneal and age, resulting in improved mechanical properties, hardness, and toughness of the alloy material.

Water Quench (Up to 2250F) & Tempering (350 – 1200F):

Water quenching is applied to water-hardening medium carbon and low carbon alloy grades of steel for improved strength, hardness, and toughness in light to moderate sections sizes. This treatment is also used in solution annealing of various ferrous and nonferrous alloys for improved corrosion resistance, or as a precursor to precipitation or age hardening.

Oil Quench (Up to 2250F) & Tempering (350 – 1200F):

This process is applied to oil-hardening medium-to-high carbon and medium-to-high carbon alloy grades of steel for improved strength, hardness, and toughness in moderate to heavy section sizes.

Forced-Air Quench (Up to 2250F) & Tempering (350 – 1200F):

This process is applied to medium carbon low alloy grades of steel for improved strength, hardness, and toughness with reduced risk of distortion. This treatment is also used in solution annealing of various ferrous and nonferrous alloys for improved corrosion resistance, or as a precursor to precipitation or age hardening.

Still-Air Quench (Up to 2250F) & Temper (350 – 1200F):

This process is applied to air-hardening grades of steel for improved strength, hardness, and toughness with reduced risk of distortion. This treatment is also used in solution annealing of various ferrous and nonferrous alloys for improved corrosion resistance, or as a precursor to precipitation or age hardening.

Selective Quench (Up to 2250F):

Selective quench is applied to parts requiring a select area to be hardened without affecting the remainder of the part.

Time-Controlled Quench (Up to 2250F):

Time-controlled quench is sometimes applied to crack sensitive parts. This process comprises parts being quenched in a fast quenching medium for a given time period before being quenched in a slower quench medium to avoid cracking while maintaining maximum hardness.