Steel Choice Matters for Corrosion Resistance
A free-machining stainless steel faces the extremely corrosive injection molding environment head on, improving machinability and stability.
Tool steel resists condensation, and waterline corrosion, which is especially important as the use of corrosive materials like fire-retardant additives, PVC and aminoplast increases. However, with every positive there is typically a negative. For example, corrosion-resistant plastic injection mold steels require additional machining time that increases wear, and more complex mold bases cause 60 percent of the steel to become chips.
To address these challenges, steel suppliers continue to develop specialty steels to combat the extremely corrosive injection molding environment while improving steel’s machinability and stability. For example, a free-machining stainless steel that offers a balance between machinability and corrosion resistance by combining a special chemical composition with a special heat-treatment process.
Low-carbon content and alloying elements such as chromium, manganese, and other additions play an important role in this free-machining stainless steel. The alloying elements are added during production and combine to yield optimal hardness, machinability and corrosion resistance (see Table 1).
C | Si | Mn | S | Cr | Additions |
---|---|---|---|---|---|
0.05 | 0.40 | 1.30 | 0.15 | 12.50 | + |
Table 2. Machining values for free-machining stainless steel (hardness 290 - 332 HB)
Mold material choice is one of the key variables influencing plastic part production profitability, so it may be time to consider the machinability, dimensional stability and weldability benefits of a free-machining stainless steel, which can also enhance mold performance with its toughness, minimal residual stresses, and good corrosion resistance.
Related Content
How to Select the Right Tool Steel for Mold Cavities
With cavity steel or alloy selection, there are many variables that can dictate the best option for moldmaking.
Read MoreAdvances in P20 Steel Potentially Eliminates Need for Stress Relieving After Rough Cutting
Omega Tool Corp. compares conventional, new P20 grades side by side in production fascia tools, finds no downside.
Read MoreHow to Achieve the Best Mold Finish
A look at factors that impact the polishability of tool steels and recommendations for obtaining a high-gloss finish.
Read MoreReliable, Efficient 3D Printer for High-Quality Tool Steel Components
The updated TruPrint 2000 underscores Trumpf’s focus on the tool and die industry, including a larger, square build plate and various features to ensure high quality and mass production.
Read MoreRead Next
Are You a Moldmaker Considering 3D Printing? Consider the 3D Printing Workshop at NPE2024
Presentations will cover 3D printing for mold tooling, material innovation, product development, bridge production and full-scale, high-volume additive manufacturing.
Read MoreReasons to Use Fiber Lasers for Mold Cleaning
Fiber lasers offer a simplicity, speed, control and portability, minimizing mold cleaning risks.
Read MoreHow to Use Continuing Education to Remain Competitive in Moldmaking
Continued training helps moldmakers make tooling decisions and properly use the latest cutting tool to efficiently machine high-quality molds.
Read More