Lork Alloy Successfully Delivers Invar Alloy Sheet To UK Customer

Lork Alloy Successfully Delivers Super-Invar Alloy Black Sheetboard Meets ASTM F1684 Standard to UK Customer

 

Author: Lork Alloy Group - Sales Department - Susan Zhang

Joint departments: Lork Quality Inspection Department, Lork Purchasing Department, Lork Technical Team, etc.
Date: November 12, 2025

 

 

The following are some of the images from this order:

 

Spectral detection video：

Order Status

 

Lork Alloy successfully delivered a batch of Super-Invar black sheetboard to a UK customer this week, with a delivery time of 10 working days. While the customer was on holiday, we completed all pre-delivery preparations in 7 days. This fully demonstrates Lork Alloy Group's unwavering pursuit of superior quality and its commitment to meeting the urgent needs of its customers.

 

In executing this order, our company strictly adhered to standardized, streamlined, and professional production and inspection processes. The delivered Super-Invar sheetboard used a dual process of hot-rolled black sheetboard and laser cutting, and underwent systematic quality testing before delivery. This fully reflects our dedication to quality, regardless of order size.

 

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Material Introduction

 

Introducing Super-Invar: A High-Performance Superalloy

 

Super-Invar is an iron-nickel-cobalt-based precision alloy with an extremely low coefficient of thermal expansion within a specific temperature range. It is primarily used for precision components requiring extremely high dimensional accuracy.

 

The superior low-expansion characteristics of Super-Invar alloys stem from its unique composition design and physical effects:

 

"Invar Effect": In iron-nickel-based alloys, when the nickel content approaches a certain range, the conventional lattice thermal expansion effect and the magnetostrictive contraction effect of ferromagnetism cancel each other out, resulting in an extremely low coefficient of thermal expansion. 4J32 further optimizes this balance by adding cobalt, achieving a lower coefficient of thermal expansion than the ordinary 4J36 Invar alloy.

 

Curie Point and Stability: It is important to note that the "Invar effect" of Super-Invar has a specific temperature range. Its Curie point is approximately 220°C. Above this temperature, the material loses its ferromagnetism, and its low expansion characteristics disappear. Furthermore, its low-temperature structural stability is poor. If the composition is not properly controlled or the processing is inadequate, an austenite-to-martensite transformation may occur at low temperatures, accompanied by volume expansion, affecting its use.

 

Material Selection and Application Recommendations

 

When choosing to use Super-Invar Alloy, pay close attention to the following points:

 

1. Define the operating temperature range: If your product primarily operates within the range of -60℃ to 80℃ and has extremely high requirements for dimensional stability, Super-Invar is an ideal choice.

 

2. Assess cost and performance requirements: Due to the presence of cobalt, Super-Invar is generally more expensive than ordinary Invar Alloy. If the performance of ordinary Invar Alloy (Invar 36) already meets the requirements, there is no need to pursue the more expensive Super-Invar.

 

3. Pay attention to material condition and processing: Super-Invar materials typically require specific heat treatment (e.g., holding at 840℃±10℃ followed by water quenching, and then tempering at 315℃±10℃) to obtain stable low-expansion characteristics. During processing and welding, care should also be taken to avoid introducing stress or altering the composition, which could affect its performance.