Deutsche Edelstahlwerke, the German subsidiary of the Schmolz + Bickenbach Group, has expanded its range of products. Since March, the new hot-working steel "ThermodurE 40 K Superclean" is now available in all dimensions from 800 x 100 to 800 x 400 mm - on request also in machined form. Nemak's Polish subsidiary is currently testing steel as the material for die casting applications that will later be used to produce 4 cylinder engine blocks.

"The material has met with great interest because it delays the formation of hot cracks and thus significantly increases the service life of the tool compared to tried and tested hot-work tool steels," explains Hans-Georg Maschetzke, Sales Manager Tool Steel EU End User at Deutsche Edelstahlwerke.

Nemak's Polish subsidiary is currently testing steel as the material for die casting applications that will later be used to produce 4 cylinder engine blocks. Approximately 300 kg weighs a single cuboid or cube-shaped insert. "The toughness and thermal shock resistance of the material are most important to us because the two properties have a significant impact on the rate of hot cracking," explains Nemak, Poland's management.

Two million castings a year

Every year, the companies in Bielsko-Biala, Poland produce around two million castings for the automotive industry. In the future, the company also intends to further expand the aluminum structural parts production in Poland, which is important in the automotive industry. The cost-effectiveness of the production and the quality of the later die-cast components depend significantly on the tool stock. "Our automotive customers place the highest demands on our castings. They especially expect flawless surfaces and absolutely precise geometries. The basis for this is a tool made of hot-work steel, which is tailored for this application, "says the head of the toolmaking division at Nemak Poland.

High expectations in the test phase

Especially the mold inserts, which give the later casting the desired characteristic shape and complexity, are exposed in the production of die-cast aluminum to an extreme environment. It only takes two minutes to produce a part. The mold inserts must withstand high pressures and temperatures above 700 ° C. "The sooner or later occurring thermal shock cracks can not be prevented, only delayed, as the ThermodurE 40 K Superclean does very effectively. Sooner or later, they will lead to the loss of form, because at the latest when the cracks grow together and breakouts occur, they would be transferred to the surface of the diecast part produced, "says Sales Manager Maschetzke.

This is confirmed by Nemak. The mold inserts from ThermodurE 40 K Superclean are now testing the company under real operating conditions. "The whole test phase lasts a good year. The parameters determined afterwards are compared with the previous values. We look closely at the surface texture, which has a direct and decisive influence on the lifetime of the tool as a whole. So far, we have been using the ThermodurE 38 K Superclean from Deutsche Edelstahlwerke for engine and gearbox housings, which has proven itself for us, "reports the management.

The expectations of the new material are therefore high. No wonder, as the company has so far produced an average of 80.000 to 150.000 die-cast parts with a set of mold inserts. Using the new hot-work steel from Deutsche Edelstahlwerke, the material after 60.000 die-cast parts must show only very little cracking. This would already have to be more pronounced for other materials at this time. Material breaks after 100.000 pieces are quite taboo. "Among other things, we expect that the ThermodurE 40 K Superclean will significantly reduce the maintenance costs for us, for example when repair welding the inserts. These maintenance measures are necessary in order to fully exploit the life of the mold frame economically. As a rule, we take a mold frame after three changes of inserts from production, "adds the head of the toolmaking division at Nemak Poland.

Full service creates trust and success

From higher tool life, lower maintenance costs, and more flexibility in die casting production, to high-quality delivery performance for die casting manufacturers and automotive customers - as much as the expectations are, so great is the optimism that this collaboration will again be successful. In any case, the start of the test phase went according to plan. Deutsche Edelstahlwerke has been supplying Nemak customers with tool steel for mold frames and mold inserts for 15 years. The 400 t reach the Polish companies directly by truck every year. The biggest contributors are the mold frames made of Formadur16, Formadur2312 and Formadur2738, which are heavy-duty moldings up to 320 t, which the steel producer delivers ready-to-install.

"In addition to the reliable steel quality, the good technical advice is an important criterion for us, especially for new projects, to repeatedly decide on Deutsche Edelstahlwerke as supplier and competence partner. Between the technical experts of both sides there is a regular exchange of experience at numerous on-site appointments ", explains the Nemak management the fruitful cooperation. Of course, this also applies during the test phase with the new ThermodurE 40 K Superclean, in which Deutsche Edelstahlwerke is a full-service provider: from technical customer advice to steel production and processing at the Witten location to hardening in our own hardening plants in Lüdenscheid. "Especially when working out the optimal heat treatment for our purposes, close cooperation with the experts is important."

They are happy about the trust that the well-known die-cast producer has given them. "The improved temperature resistance compared to the ThermodurE 38 K Superclean without significantly reducing the toughness makes the E 40 K Superclean interesting for all diecasting producers, who have to meet both the increasing quality requirements of their customers and their own efficiency demands," concludes Hans -Georg Maschetzke.