Hot ductility of an austenitic and a ferritic stainless steel

Understanding the high temperature side of the hot ductility curve for steels

“…When precipitation takes place in austenitic steels, the curves dip down, Figure 7, reach a minimum value for RA and instead of remaining relatively flat, then rise again [13]. The minimum ductility in this particular case is due to the precipitation of chromium carbides at the boundaries and within the matrix.…”

“…As with steels which undergo the ϒ/α transformation on straightening, it is the hot ductility of unrecrystallised austenite which is important in controlling the cracking susceptibility. In austenitic steels, as with HSLA, TRIP and dual phase steels which undergo transformation, increasing the strain rate and refining the grain size improves ductility whereas precipitation impairs the ductility particularly when the precipitates are situated at the austenite grain boundaries [13]. The only difference is that there is no ferrite present when straightening, so that the deformation induced thin film of ferrite (DIF) surrounding the austenite grains which is present in the HSLA steels and widens and deepens the ductility trough is absent.…”

“…Figure 7. Hot ductility curves for an austenitic stainless steel tested at different strain rates[13].…”

“…Tensile samples were heated to 1250°C and cooled at 180°C min -1 to the test temperature and strained at a strain rate of 1 × 10 −3 s −1[14]. Included in the figure are two curves from Ref [13]…”

Effect of solution treatment on the hot workability of electroslag remelted Ni−Cr−Mo alloy

“…It is well known that there are several metallurgical factors which have significant effects on hot ductility; sulfur content, grain size, precipitates and so on [5,6,[21][22][23][24][25][26]. It has been reported that the sulfur as an impurity has a detrimental effect on the hot ductility through sulfide size and morphology in low carbon steels [6].…”