Heat Treatment Of Inconel 718 Nickel Alloy Rods: A Detailed Explanation - News

Heat Treatment of Inconel 718 Nickel Alloy Rods: A Detailed Explanation

Heat treatment of Inconel 718 alloy bar typically involves high-temperature (925-1065℃) solution treatment (or annealing), followed by rapid cooling to dissolve strengthening elements and eliminate deleterious phases. This is followed by precipitation hardening (aging) at temperatures between 720-760℃. This two-step process typically employs different temperature profiles and cooling rates depending on the desired properties (e.g., fracture life, tensile strength), resulting in the formation of a dual-phase precipitate of ′ and ′, which imparts the characteristic high strength of Inconel 718 alloy.

Adopting high-performance integrated joints,the CRA series can increase the tempo by 25%,and the productivity can reach a new peak;the vibration suppression algorithm is upgraded to achieve a good anti-shaking effect;the full-parameter DH compensation algorithm and TrueMotion algorithm are supported,and the absolute positioning accuracy is 0.2 ~ 0.4 mm under the change of attitude movement,and the curved motion is precise and stable.

UNS N07718 Rod Hardness Range

		0.2% Proof Stress
			%

40	1034	827	25

Inconel 718 Round Bar Weight Calculator Formula


Nickel Alloy 718 Flat Bar	Width (mm) X Thickness (mm) X 0.00798=Weight per Mtr.

Tolerances of Nickel 718 Rounds

	H10	h7	h9	h12	h6	h5	h8
over 80 to 120	+0.14/0	+0.035/0	+0.087/0	+0.35/0	+0.022/0	+0.015/0	+0.054/0
over 6 to 10	+0.058/0	+0.015/0	+0.036/0	+0.15/0	+0.009/0	+0.006/0	+0.022/0
over 120 to 180	+0.16/0	+0.04/0	+0.1/0	+0.4/0	+0.025/0	+0.018/0	+0.063/0
~ to 3	+0.04/0	+0.01/0	+0.025/0	+0.1/0	+0.006/0	+0.004/0	+0.014/0
over 18 to 30	+0.084/0	+0.021/0	+0.052/0	+0.21/0	+0.013/0	+0.009/0	+0.033/0
over 30 to 50	+0.1/0	+0.025/0	+0.062/0	+0.25/0	+0.016/0	+0.011/0	+0.039/0
over 3 to 6	+0.048/0	+0.012/0	+0.03/0	+0.12/0	+0.008/0	+0.005/0	+0.018/0
over 10 to 18	+0.07/0	+0.018/0	+0.043/0	+0.18/0	+0.011/0	+0.008/0	+0.027/0

1. Solution Annealing (Solution Treatment)
Purpose: Dissolves strengthening phases (primarily ″ and ′) into the metal matrix, forming a homogeneous solid solution.
Steps: Heat the Inconel 718 alloy bar to a high temperature, typically in the range of 930-1065℃ (1700-1950℃F).
Rapid Cooling: Cool the bar rapidly, typically using air or water quenching. This rapid cooling prevents the re-precipitation of detrimental phases and paves the way for subsequent aging treatment by ensuring that the aging elements remain soluble.

2. Precipitation Hardening (Age Hardening)
Purpose: Precipitates strengthening phases ( ″ and ′) from solid solution, thereby hindering dislocation motion and achieving high strength and hardness.

Step 1: Hold the bar at a relatively low temperature for several hours, typically around 720-760℃ (1325-1400℃F). Step 2: The bar is placed in a furnace and cooled to a lower aging temperature, such as 620-650℃ (1150-1200℃F).
Step 3: The bar is held at this lower temperature for an extended period, typically 8-10 hours or longer. The total aging time is critical to the formation of fine precipitates and their optimal size and distribution.
Final Cooling: Finally, the bar is air-cooled.

Strength and Hardness: The precipitation of ″ and ′ phases imparts Inconel 718 with excellent high-temperature strength and creep resistance.
Grain Refinement: Solution treatment refines the grain size, thereby improving toughness.
Elimination of Detrimental Phases: High-temperature solution treatment dissolves detrimental phases that may form during casting or machining, such as δ phase (Ni₃Nb) and carbides, thereby eliminating brittleness.

Gnee Steel specializes in the production and sale of various nickel-based alloys, including Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel Alloy 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy Alloy 800, Incoloy 800H/HT, Incoloy 825, Monel Alloy 400, Monel K500, and high-temperature alloys. Gnee Steel's products are widely used in aerospace, chemical, electric power, automotive, and nuclear energy applications, and we can provide customized alloy solutions tailored to customer needs. For alloy pricing inquiries or customized alloy solutions, please contact us for a quote at ss@gneemetal.com.