Recently, an economical-type stainless steel produced by TISCO for the application of highway guardrails passed the collision tests of classes A, SB, SA and SS, granting the material access to 90% highway application. The new stainless steel, as the first of its kind in China, reaches out a key step to replace carbon steel material in making highway guardrails.

In order to extend service life, carbon steels that are galvanized with zinc to obtain corrosion resistance are traditionally adopted to make highway guardrails, said Wang Chunyang, a member of the R&D team and marketing manager of the new stainless steel grade. Compared with stainless steel, the galvanized carbon steel saved about 30% disposable investment cost. However, zinc, as a heavy metal pollutant that causes pollution to groundwater and soil, is strictly controlled by environmental protection regulations. Road construction companies begin to seek alternatives as more and more galvanizing enterprises are expelled from the qualified list, and the cost of galvanizing treatment gets higher and higher, amid deployment of the national "dual-carbon" strategy and upgrade of environmental protection requirements.

During the development of the new material, TISCO R&D team solved the strength and corrosion resistance for the highway guardrail application in the first place, and then conducted further in-depth research and experiments on the composition and production technology, and finally came up with a solution that reduces the cost by 5 percentage points, and doubled the service life. On the whole, despite the 20% more initial investment cost, stainless steel highway guardrails offer a nearly 40% life-cycle cost reduction compared with the traditional galvanized ones. Taking into account the 100% recycling ratio of stainless steel, the economic and social benefits of stainless steel highway guardrails are even more considerable.

It is understood that TISCO has reached a cooperation with Shanxi Communications Control Group, and the new stainless steel guardrails will soon be put into use on the newly-built 30-kilometer expressway in Shanxi Province. TISCO sees a very broad market prospect of the new material, as 1,000 kilometers of expressways are to be built in Shanxi Province during the "14th Five-Year Plan" period, and the total expressways mileage all around China has reached 160,000 kilometers by the end of 2021.