1.3813 Cr-Mn-N Steel Round Bar

Product Description

1.3813 (X40MnCrN19) is an austenitic, non-magnetic chromium-manganese-nitrogen steel. It belongs to the same family of high-performance alloys as the 1.3815 and 1.3817 grades you've investigated, but it is specifically optimized for high mechanical strength and exceptional non-magnetic stability under stress.

Technical Profile: 1.3813 (X40MnCrN19)

This grade is defined by a higher nitrogen content compared to the standard 1.3815. The nitrogen acts as a potent solid-solution strengthener, allowing the material to achieve higher yield points while remaining fully austenitic.

Key Properties

• Magnetic Permeability: It maintains a very low relative permeability ($\mu_r \leq 1.01$). This is stable even after severe cold deformation, making it superior for parts that must stay non-magnetic after intense machining or shaping.

• Strength-to-Weight Ratio: Due to the nitrogen alloying, 1.3813 has a higher base yield strength than many nickel-based austenitic steels, which can be further increased via cold working.

• Impact Toughness: It remains ductile and resistant to brittle fracture at low temperatures (cryogenic applications).

• Corrosion Resistance: Similar to 1.3815, it has moderate resistance. It is sufficient for indoor industrial environments and protected outdoor use, but it is not a "marine-grade" stainless steel.

Primary Applications

1.3813 round bars are typically found in high-stress electrical and mechanical environments:

• Generator Components: Particularly retaining ring segments and clamping devices where high centrifugal forces are present.

• Switchgear and Transformers: Structural parts that must not interfere with magnetic fields or suffer from induction heating.

• Non-Magnetic Tooling: Hand tools or specialized industrial equipment used near high-strength magnets or sensitive electronic sensors.

• Fasteners: High-strength non-magnetic bolts and nuts.

Comparison within the Family

Processing & Handling

• Cold Working: This is the only way to harden 1.3813. It will not harden through heat treatment.

• Machining: Like all high-manganese steels, it is "gummy" and work-hardens rapidly. You must use high-quality cobalt or carbide drills/inserts. Do not let the tool dwell. If the tool rubs without cutting, it will create a hard spot that is nearly impossible to penetrate in the next pass.

• Solution Annealing: Typically performed at 1000–1080°C followed by rapid water quenching to ensure the nitrogen and carbon remain in solution, providing the best non-magnetic properties.