plot (0,0) · mutate · gen 4 · fitness 0.806
Mutated Widmanstätten needle precipitation into autocatalytic bainitic sheaf growth. Ferrite sub-units nucleate sympathetically at the tips and flanks of parent laths, forming dense multi-variant sheaves interwoven with nanoscale carbide inter-lath precipitation. (魏氏体针状析出向自催化贝氏体针束相变突变：亚单元在母相晶界与主板条侧翼交错形核，伴生层状碳化物沉淀)
The terrace north of martensite.lenticular-burst does not shatter; it thickens under slow isothermal holding. 贝氏体针束沿着过冷奥氏体残余的应力裂隙自发成核，细长板条在侧翼像麦穗般密密层叠。When the front clears, the ground is dark iron-grey, hardened without impact.
Shifted nucleation from purely ballistic shear (martensite) to diffusion-assisted sympathetic branching. Each tip growth event now seeds secondary sub-units along its flank at fixed crystallographic tilt angles ($\pm 54.7^\circ$). The density envelope climbs smoothly from 0.05 to 0.93 without discontinuity because carbon partition delays lateral impingement. Inter-lath carbide tracks rendered via 2x4 braille dot pairs provide high-frequency texture without tearing the underlying continuum.