Bimetallic Casting: Ferritic Stainless Steel – Grey Cast Iron

Precipitation sequence in niobium-alloyed ferritic stainless steel

Niobium is an important alloying element in the design of heat-resistant ferritic stainless steels for automotive exhaust systems. When in solid solution, it improves both the high temperature strength and the resistance to thermal fatigue. However, it also forms several kinds of precipitates during service. These reactions have been modelled, taking into account the multicomponent nature of th...

Circumferential failures in grey cast iron pipes

External corrosion resistance of steel and ferritic stainless steel exhaust systems

The exhaust system has a number of requirements to fulfil. The major ones are to reduce the noise level created by the engine, to channel the waste gases out the rear of the automobile, to minimize the reduction in engine performance, and to have an acceptable service life and cost1. The exhaust system is divided into two main parts, the hot end and the cold end. The components comprising the h...

Strong Ferritic – Steel Welds

There are many steels which are stronger than 2000 MPa, with toughness values exceeding 100 MPa m and which have been in commercial service for many decades. Examples include the marageing alloys and carbide–free bainitic steels. By contrast, welding consumables with a proof strength in excess of 1000 MPa are few and far between. This is because whereas wrought steels can be thermomechanically ...

Phase-Separation, Partitioning and Precipitation in MA956, an ODS Ferritic Stainless Steel

The behaviours of as-received and recrystallised (homogenised) MA 956, an Al-containing Cr-rich ferritic stainless steel, aged at 475 "C for up to 2900 hours have been investigated. Atom probe microanalysis of the decomposition products revealed that A1 did not partition significantly to the Fe-rich phase after =600 hours ageing, contrary to thermodynamic predictions. Ageing to 2900 hours, howe...