Fig. 1 a Engineering stress-strain curve of 316L stainless steel, b schematic diagram of the sample geometry and EBSD data acquisition region

Fig. 2 a IPF-mapping, b phase distribution map, c KAM map of the sample after heat treatment. The color bar in c shows the extent of stress concentration

Fig. 3 a, b IPF-mapping and band contrast (BC) map of 316L stainless steel at engineering strain of 0.2 showing the deformed twin bundle, c, d IPF-mapping and BC map of 316L stainless steel at engineering strain of 0.4 showing the deformed twin bundle and martensite (white area in the IPF-mapping), e IPF-distribution of grain orientation in the RD direction (RD∥tensile direction) at different engineering strains

Fig. 4 BC map a, IPF-mapping (white area is martensite) b, phase distribution map c and KAM map (gray area is martensite) d for engineering strain of 0.2, respectively; e the maps (IPF-mapping and KAM map) of the rectangular frame in b, and the pole map at the cross position of the twin (showing the angular axis relationship between the twin and the matrix). Figure 4 is a local magnification of the white rectangular box in Fig. 3a. Here we call the larger twin Twin1 as primary twin and the smaller twin Twin2 as secondary twin

Fig. 5 IPF-mapping (white areas are martensite) a, phase distribution map b and KAM maps (gray areas are martensite) c for the sample with engineering strain of 0.4, respectively; d local magnification of the rectangular frame in (a); e local amplification of IPF-mapping of the white square in (d). Figure 5 is a local magnification of the white rectangular box in Fig. 3c

Fig. 6 TEM analysis results when the engineering strain is 0.2: a bright field (BF)-TEM image, b SAED pattern obtained along the [011] axis of the twin part in (a)

Fig. 7 TEM analysis results when the engineering strain is 0.2: a BF-TEM image, b-d HRTEM images of the rectangular areas in (a) and corresponding fast fourier transform (FFT) patterns. Twin1 is called the primary twin, and Twin2 is called the secondary twin

Fig. 8 a, b BF-TEM images at engineering strain of 0.4 and selective area diffraction patterns (SAED) along the [011] axis, respectively; c dark field (DF) -TEM images of crossed twins and martensite; d, e HRTEM image of the white rectangular box in (a) and the corresponding FFT pattern, respectively

Fig. 9 a Strain hardening rate curve, b-d schematic diagrams of the microstructure evolution of 316L stainless steel during strain. A-B-C in b represents three different grain orientations, A: < 111 > //RD, B: < 001 > //RD, C: < 110 > //RD. Note that the strain here is true strain (the true strains 0.18 and 0.34 corresponding to engineering strains 0.2 and 0.4, respectively)